Implementation of control plans in digital format
João Frederico Pereira Correia
Dissertação de Mestrado
Orientador na FEUP: Eng. Eduardo Gil da Costa Orientador na Empresa: Eng. Eva Castro
Mestrado Integrado em Engenharia Industrial e Gestão
“The very basic core of a man's living spirit is his passion for adventure. The joy of life comes from our encounters with new experiences, and hence there is no greater joy than to have an endlessly changing horizon, for each day to have a new and different sun” Christopher McCandless 1968-1992
Resumo
A presente dissertação foi desenvolvida na fábrica Bosch Termotecnologia, Aveiro, como parte do Mestrado Integrado em Engenharia Industrial e Gestão da Faculdade de Engenharia da Universidade do Porto, com o objetivo de apresentar o trabalho desenvolvido na implementação de planos de controlo em formato digital.
Atualmente a folha de controlos é preenchida manualmente. O principal objetivo deste projeto consiste na implementação de planos de controlo em formato digital, através do uso de um
tablet, que será usado pelos operadores com o intuito de fornecer informação sobre os processos
e medições necessárias, previstas no plano de controlo.
A utilização de planos de controlo neste formato oferece muitas vantagens, tais como a presença de fotos das peças e equipamentos de controlo, mobilidade e uma interface amigável. Este formato facilita o fluxo de informação e a disponibilidade de conteúdos para os trabalhadores diretos assim como para a engenharia da produção. Esta opção também é economicamente menos dispendiosa e permite uma organização e análise de informação mais sofisticada. O projeto consiste em três etapas iniciais: revisão e aprovação de planos de controlo, edição de instruções visuais de controlo e trabalhos nas secções de forma a recolher informação sobre códigos de material e controlos específicos. Adicionalmente, há também duas etapas finais: formação dos operadores no uso do tablet e um período de estabilização, após o qual é realizado um levantamento de informação, a fim de realizar ajustes com base no feedback dos operadores.
Implementation of control plans in digital format
Abstract
The present dissertation was developed at Bosch in the context of the Integrated Master Degree in Industrial Engineering and Management at the Faculty of Engineering of the University of Porto with the aim of presenting the work developed in the implementation of control plans in digital format.
Currently the control sheets are fulfilled by hand. A major objective of this project consists in the implementation of control plans in digital format, using a Tablet, in order to be used by the operators and supply them with complete information about the processes and measurements required in the control plan.
The utilization of control plans in this format offers many advantages, such as the presence of part and equipment photos for each control, mobility and user-friendly interaction. It eases the information flow and availability of content for both the worker and the production engineer. It also helps with the economy of paper and organizing and analysing information.
This project consists of three initial steps: review and approval of control plans, edition of visual instructions of control in a back-office software and works on the section to gather information about material codes and specific controls. Additionally, two final phases have been implemented: training of operators in the use of the Tablet and a stabilization period, after which a survey has been conducted, in order to make adjustments based on operators’ feedback.
Acknowledgment
In order to accomplish this dissertation work, several people contributed, to whom the author would like to express his gratitude:
- The mentor at Bosch, Eva Castro, and the mentor at the faculty, Eduardo Gil da Costa, for their support, teachings and exceptional availability.
- To Richard António, Paulo André Costa, Armando Oliveira, Leonel Monteiro, Paulo Oliveira and many more that contributed in this project for the support and help with the works in the section.
- To the colleagues in the project, Manuel Bravo, Mário Rei, Miguel Cunha and João Viveiros for their friendship, assistance and integration within the project and the company.
- To a fellow colleague Luís Marques at the faculty and now at Bosch that helped me with my integration.
- To Fernanda Silva for the support and availability in documentation management and IT problem-solving.
- To the process engineers Filipe Pinto, Hélder Vieira, Alexandre Cardoso, José Ribeiro for the teachings about the processes in sections they are responsible for.
- To Anabela Vendeiro, Sílvia Silva and Margarida Pereira for the support using SAP software.
- To all employees who worked directly or indirectly in carrying out the project and who were responsible for creating an ideal environment for its success.
- To the Faculty of Engineering of the University of Porto, Faculty of Engineering of Buenos Aires and Kasetsart University for all the teachings and training that facilitated a good adaptation to the work environment.
- To Bosch Thermotechnology for the opportunity to work in this project and this plant, and for all the knowledge and competencies developed during the internship.
- To Carlos Gonçalves, director of production, for giving the opportunity to sign a contract in order to continue this project.
Index
1 Introduction ... 1
1.1 Bosch Thermotechnology presentation ... 1
1.2 Scope of the project ... 1
1.3 Sections where the project was implemented ... 2
1.4 Method followed in the project ... 3
1.5 Dissertation Structure ... 5
2 State of Art ... 6
2.1 Quality ... 6
2.2 Process Control ... 6
2.3 Information Systems ... 7
2.4 Process Failure Mode and Effect Analysis, PFMEA ... 7
2.5 Control Plan ... 8
2.6 Kanban System ... 9
2.7 Quick-Response Codes ... 9
2.8 Plan-Do-Check-Act Cycle ... 9
3 Project Analysis ... 11
3.1 Scope of the project ... 11
3.2 Back-office Software (WCPL_MAN) ... 12
3.3 Front-office Software (WCPL_REG) ... 14
3.4 Conversion Plan ... 19
4 Project Development ... 20
4.1 Guidebook ... 20
4.2 Difficulties and lessons learned ... 22
4.3 Improvements ... 23
4.4 Analysis of Surveys ... 25
5 Conclusions and prospects of future work ... 28
References ... 29
Acronyms
BOM – Bill of Materials
CKD – Component Knock Down CP – Control Plan
FMEA - Failure Mode and Effects Analysis
MOE – Manufacturing and Operations Engineering
MOE1 – Manufacturing and Operations Engineering – Sub department 1 MOE2 – Manufacturing and Operations Engineering – Sub department 2 MOE3 – Manufacturing and Operations Engineering – Sub department 3 MOE4 – Manufacturing and Operations Engineering – Sub department 4 PDF - Portable Document Format
S871 – Section 871 S851 – Section 851 S852 – Section 852 S872 – Section 872 S856 – Section 856 S857 – Section 857 S855 – Section 855
Figure Index
Figure 1 – Sections where the project was implemented in the scope of this dissertation ... 3
Figure 2 – Project timeline ... 4
Figure 3 – Visual Instructions of Control – Back-office ... 13
Figure 4 – Tablet integrated scanner ... 14
Figure 5 – Station card and operator’s card QR code... 14
Figure 6 – Login Menu of WCPL_REG software ... 15
Figure 7 – Main Screen of WCPL_REG software ... 16
Figure 8 - Iniciate controls ... 16
Figure 9 - Kanban and Station Card ... 17
Figure 10 - Example of controls ... 17
Figure 11 - Example of a non-measurable control ... 18
Figure 12 - Example of a measurable control ... 18
Figure 13 - Overview of the total number of control plans ... 24
Figure 14 - Graph of the number of times each worker used the Tablet ... 26
Figure 15 - Graph of the workers’ preferences... 26
Figure 16 - Graph of the workers’ opinion on the control times ... 26
1 Introduction
This document aims to present a project developed at Bosch Thermotechnology, SA in Aveiro designated by "Implementation of control plans in digital format", carried out under the course "Dissertation" of the 5th year of the MSc in Industrial Engineering and Management, Faculty of Engineering, University of Porto.
The aim of the dissertation is to apply the knowledge acquired during the Integrated Master and enable a first experience in an enterprise environment.
1.1 Bosch Thermotechnology presentation
Bosch Thermotechnology represents the Thermotechnology Division of the Bosch Group. The Aveiro plant is part of this division and is responsible for the production of instantaneous gas water heaters, wall mounted condensing boilers, heat pumps and components knock down, CKD.
Present in 55 countries and different markets, from Europe to Australia, Bosch Thermotechnology produces a wide range of models that are marketed internationally through own brands of the Group (Bosch, Buderus, Junkers, Leblanc, Vulcano) or customer brands. European market leader since 1992, and third world producer of water heaters, Bosch Thermotechnology SA is now the Robert Bosch competence center for this product, being responsible for the design and development of new devices and their production and marketing. Under the name of “Vulcano Termodomésticos SA”, Bosch Thermotechnology SA started its activity in Cacia - Aveiro, in 1977, based on a licensing agreement with Robert Bosch for the transfer of technology used by the German company in water heaters manufacturing.
In 1988, the company was acquired by the Bosch Group, who moved skills and equipment to Portugal, starting a process of specialization within the Group.
1.2 Scope of the project
The project was developed in the Manufacturing and Operations Engineering, MOE department, under the name of “Control Plans Project” and it is a pioneer in Bosch. Its main objectives are to improve information flow and organization, documentation management and create a standard form of fulfilling the control plans. Aside from these improvements this
1.3 Sections where the project was implemented
For the scope of this dissertation, it will be analyzed the implementation of control plans in digital format for sections of the Manufacturing and Operations Engineering 1, MOE1 (Comfort section), and Manufacturing and Operations Engineering 4, MOE4 (High-Output section), which are positioned within the plant as it is possible to see in Figure 1.
Section 871, S871 (Cell 1 and Cell 3)
Responsible for the production of the models Compact Baterias, Compact Tico-Piezo, Compact HDG, Compact 6L, VMC, CAE, CAE Baterias and KME in the Comfort section.
Section 872, S872 (Line 8)
Responsible for the production of the models FP, FPDNA, World 2 and World 3 in the High-Output section.
Section 851, S851 (Chiron, CAE, SERI)
Responsible for the production of valves, collectors and CAE gas valve in the Comfort section.
Section 851, S851 (CPT1 and CPT2)
Responsible for the production of gas valves Ticos, Baterias and Compact 6L in the Comfort section.
Section 852, S852
Responsible for the production of water valves in the Comfort section, W and WR models.
Section 857, S857
Responsible for the production of water valves in the High-Output section.
Section 856, S856
Responsible for the production of gas valves Baterias, Integrados and TA in the High-Output section.
Section 875, S875
Figure 1 – Sections where the project was implemented in the scope of this dissertation
1.4 Method followed in the project
In Figure 2 is possible to see a timeline of the work developed for each section during the period starting in the week 10, that marked the beginning of this project after the implementation in the pilot section, section 855, S855, and ending in the week 39.
For each section the project is divided in five phases, review and approval of control plans, visual instruction of control editing, VICO, section works, go-live and a stabilization period from 2 weeks to one month, depending on the complexity of the controls and number of references in the section.
Figure 2 – Project timeline
Review and approval of control plans
- Order Tablets and drawers
- Solve inconsistencies between paper and WFVB_DOC - Gather knowledge of the processes in the section
- Confirmation of the specifications in product standards and torques table
- Confirmation of the stations inventory numbers on the section and WGMT_EQU
- Review, correction, adaptation and updating of control plans
- Send Control Plan for approval
VICO Preparation
- Images collection of parts and control equipment
- Image editing and importation into the computer system - back-office
Section Works
- List of references for each feature control
- Print QR codes for employees’ cards
- Creation and establishment of post cards with QR code
- Print data matrix codes for each product reference (if the Kanban system is not working at one particular section)
1
2
Go-live
- Implementation and training of operators
Stabilization period
- Period from 2 weeks to one month to make sure the controls and respective photos are all correct.
1.5 Dissertation Structure
In chapter 1 it was made a presentation of Bosch Thermotechnology, Aveiro plant and its origins and the scope of the project. It was also presented the sections where it was implemented this system and the method followed throughout the project from the start until its full implementation.
In chapter 2 it will be described the theory this dissertation was based on with explanations about control plans, failure mode and effect analysis, kanban system and preventive maintenance.
In chapter 3 it will be presented the scope of the project in more detail and its overview and analysis.
In chapter 4 there will be a guidebook for the project to be implemented in other sections of this plant and in other plants in general. It will also be described some of the difficulties, lessons learned from them and the impact this project had to improve the quality of process controlling. Finally, there will be a data analysis of surveys, fulfilled by the employees, in order to obtain their feedback and gather knowledge about their preferences.
In chapter 5 it will be described the next steps for this project, side-projects, continuous improvement of the control making processes and thoughts about other purposes for the Tablet to create value for the company.
4 3
5 3
2 State of Art
In this chapter it will be described the theory this dissertation was based on with explanations about quality, process control, information systems, process failure mode and effect analysis, control plans, Kanban system, Quick Response Code and Plan-Do-Check-Act Cycle.
2.1 Quality
“Quality represents a driver that produces higher profits through lower costs and the ability to command a premium price in the marketplace” (Thomas Pyzdek and Roger W. Berger, 1991). Nowadays, due to the increasing competitiveness of the markets, along with a never-ending increase in product variation, enterprises face a challenge in lowering costs of production. Constantly improving the quality of the products and processes has become the most critical step to attain this goal and thus, improve market share within the industries it operates on. However, there are costs associated with quality improvement and companies must find the correct balance of these, maximizing the total value of quality.
According to Thomas Pyzdek and Roger W. Berger (1991), quality costs are the total of the costs incurred by:
a) Investing in the prevention of non-conformances to requirements;
b) Appraising a product or service for conformance to requirements; c) Failure to meet requirements.
Thus, it is possible to create value by investing in the prevention as it will decrease the quantity of products that fail to meet requirements and the need for re-work and scraps. This not only translates to a lower overall cost of production as it also boosts the level of perceived quality and sense of trustworthiness by the customer.
2.2 Process Control
"A phenomenon will be said to be in control when, through the use of past experience, we can predict, at least within limits, how the phenomenon may be expected to vary in the future. Here it is understood that the prediction within limits means that we can state, at least approximately, the probability that the observed phenomenon will fall within given limit" (Shewhart, 1931) The process control should serve two main purposes. The first is to guarantee that the equipment in each station is able to function as it was conceived to be, in order to enable the production control. This is a critical step to make sure that controls made on the product are accurate. The second purpose is to gather information about process reliability and variation, by analyzing the historical behavior of the equipment. This is especially important as it enables the maintenance responsible to act before the equipment measures get out of the specified standards.
By improving process control the prevention costs increase as a consequence but it also decreases the percentage of defective products (George W. Roberts, 1994). Once again, it is required to find a balance between prevention costs and the benefits of a higher percentage of flawless products, so that the total value of this sum is maximized. Thus, process control points are selected to maximize the amount of control obtained at minimum cost (Thomas Pyzdek and Roger W. Berger, 1991).
2.3 Information Systems
“A major quality-engineering technique is the use of modern data processing equipment and computers, integrated into all relevant areas of quality control. This not only can speed up the timeliness of quality information… but in some cases can make possible information flow that could not otherwise exist” (Armand V. Feigenbaum, 1991).
Presently it is already possible to see the benefits a fully implemented information system brings to an enterprise. By adopting all the available and relevant technology, it is possible now more than ever to maximize the use of information. Data is the key to any company that wishes to succeed.
2.4 Process Failure Mode and Effect Analysis, PFMEA
A process failure mode and effect analysis, FMEA, is an analytical technique utilized as a mean to assure that potential failure modes and associated causes have been considered and addressed (Chrysler Corporation, Ford Motor Company, General Motors Corporation, 1993).
For each failure mode, the causes and effects are studied and the risk is calculated based on three fundamental characteristics:
- Severity (S) – Degree of consequences, assuming that the cause and failure mode have arisen.
- Probability of occurrence (P) - Probability that the potential cause of failure will occur. - Detection (D) - Probability that a non-conform product will reach the customer,
assuming that the cause and failure mode have arisen.
“When for a given item the product of (P) x (D) x (S) is 9 or greater, the item is recognized as critical. In cases where critical parts cannot be eliminated, Quality Engineering must establish in quality planning very stringent process control, inspection and testing for such items.” (Armand V. Feigenbaum, 1991)
This analysis helps engineers identify which processes are critical and improve their control characteristics and frequency of inspection in order to increase the probability of performing with success and safety. It also provides a documented method that recommends actions and serves as a basis for troubleshooting problems.
The production control plan is based on this analysis and as such, it is an output of the PFMEA. By conceiving a failure mode and effect analysis it is possible to improve the quality, reliability and safety of the evaluated products and processes, therefore improving customer satisfaction.
2.5 Control Plan
The production control plan is a written description of the systems for controlling parts and processes. The production control plan, as a living document, identifies and communicates changes in the product /process characteristics, control method, and characteristic measurement and should be updated to reflect the addition/deletion of controls (Chrysler Corporation, Ford Motor Company, General Motors Corporation, 1994).
The Control Plan describes, for each process or test step of a product, the necessary actions and allowed tolerances to assure that the process is in control and the required quality is maintained. It is used during the planning and operation of production processes and must therefore always reflect the current state.
The Bosch Thermotechnology standard control plan can be consulted in Annexe A.
For explanation purposes, the detailed description of a control plan has been divided in two categories:
Document description
The first step in the creation of a control plan is to define for which production phase it will be applied, prototype, pre-launch or production. Then a control plan number is attributed and there must be recorded the parts number and name these controls should be applied to. Following this there are a series of characteristics such as name of the company or plan, supplier code, key contact, the names of the persons that formed the core team that developed the control plan and finally dates of original document creation, approval and revision, as well as the number of the revision, following a numerical order (Chrysler Corporation, Ford Motor Company, General Motors Corporation, 1994).
Control Information
For each control it is required a sequential number in order to easily identify each control within the control plan, followed by a description of the production operation it refers to, as also the inventory number of the production station, machine, device or jig involved in this step of production. Next to this column it should be stated the number of the process FMEA it was based on and the exact line where the risks have been evaluated and the detection or prevention measures are defined. If it is the case that the control step was not analyzed in a PFMEA document it should be written Not-Applicable, N/A. (Chrysler Corporation, Ford Motor Company, General Motors Corporation, 1994).
There are two columns, one respective to product characteristics and another to process characteristics. Only one of these should be fulfilled, depending if it is a process or product control. Next it should be indicated a classification of special characteristics such as functional, that affect a function in the final product, and safety and/or governmental, that affect compliance with legal requirements or safety of the final product, or no classification at all. The next 3 columns, prevention devices associated with the control, maintenance plan and machine capability are optional.
The control step should end with the indication of product/process specification and tolerance, measurement equipment, sample size, frequency, described control method and a reaction plan, the procedure to follow in response to non-conformities.
The main purpose of the control plan is to aid in the manufacture of products according to the customer requirements and are either based on the experience gained through the years in the industry or on FMEA documents.
2.6 Kanban System
"The operating method of the Toyota Production System is kanban. Its most frequently used form is a piece of paper contained in a rectangular vinyl envelope" (Taiichi Ohno 1988).
Kanban is an inventory control system for the supply chain developed to improve
manufacturing efficiency. In the scope of the project, kanban papers of the references produced in each section serve the purpose of identifying the controlled product.
The fame of the Japanese Kanban system has heightened interest in the “pull” system of product control as opposed to the old “push” system. In the latter, operators only worry about production and creating inventory, so that machines and people are always busy, without considering inventory costs and the lack of need for the products. In the “pull” system each workstation produces the exact amount needed by the next station. Kanban cards support the “pull” system in the inventory control system (Keki R. Bhote, 2003).
2.7 Quick-Response Codes
Quick-Response, QR codes were first created back in 1994. A Toyota subsidiary named Denso
Wave developed the code in order to help in the manufacturing process, they aided in tracking vehicles and parts. It was designed to allow for fast decoding speeds, hence the name Quick Response code. QR codes owe their existence to the development and success of barcodes. Since their creation barcodes became very popular due to the speed at which they could be scanned, the accuracy they provided, and their multiple functionalities. With increased popularity, and proper recognition of the convenience associated with barcodes, demand for barcodes that could store more information, had more variation, and would take up a smaller printing area continuously grew (http://www.mobile-qr-codes.org/history-of-qr-codes.html).
2.8 Plan-Do-Check-Act Cycle
“The most important objective to develop consistent understanding of and alignment to the plan. Resources will surely be wasted and results minimized if the plan is unclear or if everyone is not aligned to the task” (Jeffrey K. Liker and David Meier, 2005).
Plan - Define the objectives and goals, describe the tasks necessary to achieve those objectives
and draw an implementation plan with breakdown of each task, owner, expected outcome, operating procedure or guidelines etc.
This project was developed using Plan-Do-Check-Act, PDCA, as a basis for project management. There was an initial conversion plan for the project to be implemented in each section that followed this concept.
In the planning phase, for each section, it was defined a sub-project manager and an intern to give support. The responsible for each step of the conversion plan was defined and it was made an analysis of the time it would take to conclude the implementation in order to allocate time so that the deadlines were met. The “Do” phase was the implementation itself, from the beginning until the training of the operators in the use of the Tablet.
The next step was to check if the controls were being made through several process confirmations and act accordingly if there are missing controls and make improvements based on feedback, since every section has its own particularities.
3 Project Analysis
In this chapter it will be presented the scope of the project in more detail and its overview and analysis. There will be a presentation about the software used in the back-office, for Visual Instructions of Control, VICO, that enables the process engineer to consult a database of controls and change photos, references and control station numbers for each control. For the front-office software, available to process engineers, quality responsible and workers that perform controls, there will be a short presentation about its capabilities.
Finally, it will be presented the conversion plan that serves as a basis for this project.
3.1 Scope of the project
In this subchapter it will be described the expected general improvements within the plant as an output of this project.
Documentation Management
While all the control plans in excel format are correctly organized in FVB_DOC, an internal folder with all the approved documentation, the same doesn’t happen for control plans based on FMEA analysis. One of the reasons for this is that in the past the control plans from IQ-RM were exported in Portable Document Format, PDF, which cannot be directly modified. The solution to this problem was to edit the control plans directly in IQ-RM and then export for excel, as this option became possible for the first time this year. However, there were difficulties finding most of the FMEA files and respective work-on, the file that serves as proof that the FMEA was approved. One of the side objectives of this project is to facilitate the access to these documents by clearly organizing all the data through a software, in order to have the most recent files available to everyone who needs it. Nowadays this organization is made just by using an excel spreadsheet.
Saving paper and eliminate waste
Having more than six hundred control plans in utilization, with shifty, daily and weekly controls, this translates into thousands of sheets per week, which are rather costly to the enterprise. Besides this, the registry of the controls was archived and stored, just being used when an audit was taking place and there was almost no use for the information, which takes us to the next topic.
Information flow and organization
Registering the controls in paper sheets creates waste and adds little value to the company as nowadays these controls are archived and of difficult access since there is too much information to analyze. Integrating these controls in a software application will make possible, for the production engineers, to consult and analyze information in real time, allowing them to take measures quickly and efficiently.
Having the information stored on a computer system will allow the process engineer and the quality responsible to actively gather knowledge about the state of the processes. When it is
process as the necessary adjustment can be made even before the characteristic gets out of specification. This allows for a much regular and efficient maintenance.
Also, by implementing this project across all of Bosch Thermotechnology plants, it will be possible to correlate performance metrics across multiple plans.
Standard control plan organization for all the production sections
Despite having a standard template for the control plans, nowadays each process engineer makes his control plans in a way he sees fitted, creating difficulties for the person who analysis it. Some control plans also have incomplete, incorrect or out-of-date information and this project allows their update and completion, since the software filters everything and does not permit empty fields for many spreadsheet cells.
Preventing errors from the workers’ part
Nowadays, for some controls, the worker has to make calculations to see if the characteristics are within its specification.
The updated control plans in the Tablet prevent the workers from making mistakes because the software used in the Tablets is prepared to make the necessary calculations with a simple input from the workers. Also, if there is a non-conformity the worker cannot advance to the next control until he/she writes an observation of the problem and how it was solved, following the procedure stated in the reaction plan, present in the control plan.
The same principle applies for operators who have difficulties understanding a design standard, either because they have no knowledge of technical drawing whatsoever or because the drawings are too complex. By having photos of the parts and equipment test, this is no longer a problem, as they clearly identify which and where each control is made. The ambiguity of some controls is eliminated, making it harder for the operator to error. This way the general probability of human error while making a control is much lower than it would be otherwise.
3.2 Back-office Software (WCPL_MAN)
The back-office software used for VICO editing and control consulting was internally developed at Aveiro Plant as a tool to assist with this project and its name is WCPL_MAN. Along this sub-chapter the main characteristics and functionalities of this software are explained.
As it is possible to see on Figure 3, there are five horizontal menus.
“Planos de controlo”, Control Plans, is used to import or reimport control plans and it is only possible to import control plans after they have been approved and placed in a particular folder that can only be accessed by the document management responsible.
“Instruções Visuais Controlo”, Visual Control Instructions, is used to edit visual instructions of control.
On menu “Controlos”, Controls, is possible to access the database of all the controls made within the plant and use filters to easily search for controls in one section, station many more options.
Menu “Tabelas”, Tables, is used to access a database of images, operators, among others. This is an important feature because it allows to search for any images that were already uploaded to the software.
Finally, there is a “Testes”, Tests, menu to make tests and guarantee that the software accepts certain expressions of specification or frequency.
VICO Editing
There are six main attributes for the edition of visual instructions of control. Defining the trainers, typically the team and shift responsible, and selecting their names from a central database. These trainers are the persons responsible for the training of the workers in the use of the Tablet.
The references of the products produced in one section, for each line of control, should exclusively be the ones of the products that have the product characteristic specified. This list of references should be saved on material codes.
The next step is to indicate the inventory number of the station for each control. This number must be the one of the control station and not of the station where it is produced.
For each characteristic it must be uploaded or chosen from the image directory the part and equipment photos.
Finally, the starting date must be indicated. This can be the go-live date or a date from which some control should begin to be made, after it was created or modified by the process engineer. In the particular case when there is a control with a frequency of 100% and there is no need for recording the results, these characteristics should be defined in “Planos de Controlo” as “Sem IVC”, without VICO, and do not appear in the Tablet application despite being in the control plan.
3.3 Front-office Software (WCPL_REG)
The front-office software used to perform the controls on the Tablet was internally developed at Aveiro Plant and named as WCPL_REG.
Every Tablet has an integrated scanner that allows to read QR Codes and Kanban card codes, easing and speeding-up the control process (Figure 4).
Figure 4 – Tablet integrated scanner
There is at least one Tablet and drawer for each section. The drawer should have a card just like the one on Figure 5. This card functions as a method to login into Windows as it contains the password in the QR Code, so that it is possible for the worker to login to Windows without needing to remember the password.
After opening the application, the screen on Figure 6 is shown and the user must login to the application using their own QR Code (Figure 5). This code is fixed on every workers’ ID card as it is required for them to identify themselves.
Figure 6 – Login Menu of WCPL_REG software
After logging-in on the application, there should appear the name of the worker on the upper-right corner. Depending on the person making the controls, the menu “Formação”, Training, can appear or not, as only the persons defined in the back-office software as trainers should have this menu.
As shown on Figure 7, there are 9 main menus: “Iniciar” to start a control,
“Continuar” to continue a control left opened,
“Formação” to train someone on the use of the Tablet and on the particular controls one worker has to make.
“Consulta”, for the user to consult the controls made by using the menu and see every control that exists for one reference and station on the menu “Pesquisa por TTNR/Posto”, Search by TTNR/Station,
“Legenda” shows the meaning of every icon used in the software.
There is also a series of menus for the “Parâmetros de Processo”, Process Parameters, as they are starting to be included in the control plans on a side-project to this one but that won’t be discussed in this dissertation.
Figure 7 – Main Screen of WCPL_REG software
By selecting “Iniciar” the screen on Figure 8 shows up. The first step is to scan the card present on the section. If it is the case that the control is on a process, scanning the card will be enough, since it is not associated with any product. If it is a control on a part / product the Kanban card of the cycle of production of this product should be also scanned. It is possible to see examples of both these cards on Figure 9.
Figure 9 - Kanban and Station Card
After searching for the control the next step a user has to follow is to choose an option on the lower bar:
- “Troca referência”, Part change, if the control is being made because of a change in reference.
- “Troca Mat. Prima”, Raw material change, if the control is being made because of a change in feedstock.
- “Troca Ferramenta”, Tool change, if the control is being made because of a change of tool.
- “Nº de peças”, Number of parts, if the control is supposed to be done after a certain number of references produced.
- “Por tempo”, By time, if the control is supposed to be done at a certain frequency of time, usually start of the shift, one time per week or month.
After choosing one of this options, the controls with frequency of control selected are automatically selected and the user just has to initiate them.
In figure 11 it is possible to see an example of a non-measurable control. In order to make the control the operator has to register if the characteristic is in conformity with its specification or not. This is an OK / Not OK type of control.
Figure 11 - Example of a non-measurable control
In figure 12 it is possible to see an example of a measurable control. In order to make the control the operator has to register a value.
When a control is out of specification a reaction plan appears on the screen, in order for the worker to know what to do. In these cases, the user cannot continue a control first justifying what was made to rectify it.
3.4 Conversion Plan
The conversion plan is a document created with the objective of explaining, step by step, the required works until the implementation is completed. This document reflects the experience of the project managers on the pilot section, S855, which will not be discussed in this thesis.
4 Project Development
In this chapter it is presented a guidebook, produced with the intention of serving as a basis for the implementation of this project in the other sections of Aveiro plant as in other Bosch Thermotechnology plants. There is list of difficulties found throughout the project, how they were overcome, lessons learned, improvements and a survey analysis.
4.1 Guidebook
In this sub-chapter each implementation step is clearly defined and it is presented a compiled list of relevant SAP transactions.
Review and approval of control plans
- Solve inconsistencies between paper and WFVB_DOC – Check if the printed control plans in the section are the same as the computer archived version.
- Gather knowledge of the processes in the section – Based on the current control plans, understand which processes exist and the controlled parts.
- Based on the number of controls and their frequency in one section, choose how many Tablets are required.
- Order Tablets and drawers from a supplier.
- Product standards and torques table – Confirm that the specifications indicated in the control plan meet specifications in the product standards sheet and torques Tablet.
- Confirmation of the stations inventory numbers on the section and WGMT_EQU (Equipment management software within Bosch Thermotechnology) to confirm that the inventory numbers of the stations are accurate to the numbers present in the control plan. This is an important step since in the VICO edition the system will be connected to the SAP database and if some inventory numbers are not correct it is not possible to establish a connection.
- Review - Correction, adaptation and updating of control plans
For eachtorque wrench, confirm the minimum and maximum torque they are able to analyze and update in the control plan their number, only in controls of tightening torques that are within this range.
There are control plans in excel format and in IQ-RM - these are the most recent ones, from a software dedicated to the conception and edition of FMEA, as of respective control plans.
Fill every cell following the rules specified by the software, so that the control plan might be imported without errors.
Eliminate control characteristics of models or references that are no longer produced. - Send Control Plan for approval. Each control plan must be approved by the process
engineer responsible for the section the control plan refers to, the production and plant director.
VICO Preparation
- Trainers – Define and select the trainers from the database
- Material Codes – In the case of product characteristics, insert references that contain the controlled characteristic for each line of control. In the case of process characteristics material codes are not necessary since they only control the process and not the product. - Control Stations – Insert the inventory number of the station where one particular characteristic is controlled. Sometimes this is a different station from the one where it is produced.
- Associate photos
- Define a starting date – Go-live date.
Section Works
- Print QR codes for employees’ cards – Every operator needs this QR Code to login to
the application.
- Creation and establishment of post cards with QR code – Every station where there is a control must have this code.
- Print data matrix codes for each product reference (if the Kanban system is not present at one particular section)
Go-live
- Training of the operators
Stabilization period
- Make changes in accordance with operators’ feedback
Important SAP transactions for this project:
cOOis – Consult production orders and current state of production, in order to know when to take photos of each model.
Z23CRUU_EXPORT_REQ – This transaction shows the lists of requirements for each reference for each week. This transaction is especially important in sections where there are produced exotic models, in some cases only one cycle of production a month.
CL30N (and then Z23_BIP) – Shows all the references produced in one or more sections. CV03N – Consult product data standards, to access the tightening torques values and other standard tests, making sure that every control plan is in agreement with these specifications.
Alternatively, one can use the Z23MMUU_BOM_DATA for both structured BOM and reverse structured BOM.
4.2 Difficulties and lessons learned
In this sub-chapter it is presented a list of the main difficulties found throughout the project, how they were overcome and lessons learned.
Process and Product Characteristics
The first difficulty was to find a standard control plan, in accordance with the software filtering, so that no information was lost. In most control plans the standard was written in “Process Characteristic” while the “Product Characteristic” contained the characteristic being controlled. Since the software only allows one of them, the information on both must be compiled on one or another.
The first step was to clearly distinguish what was a process or product characteristic and put all the information together, in order to be possible to answer to an auditor on what standard each specification was based.
These distinctions are also important because process controls are independent from product references and therefore a user controlling a process characteristic should not have to scan a product reference. Although this is conceptually true, it created some problems because there are process controls that only take place when some products are produced. Due to this problem, exceptions to this rule were created. One of this exceptions was made on S851 CPTs, a section that produces the gas valves "Baterias and Ticos". If only one model was produced in a given day, the process control in some stations was left blank and therefore makes it difficult to know the cause when a process confirmation takes place. By creating a link between the process and the product in these cases it is possible to only make the process control required to produce a certain model.
Stations with NTC system
There are some stations (particularly for the tightness tests) that have a system called NTC. This system automatically sends the results to the computer system and are registered in a database accessed through a software called WMAN_POS. Therefore, there is no need of registering the controls in the Tablet.
Kanbans
In the scope of this project, kanbans were thought to be used to scan the product references. Despite this, there are a few sections that don’t produce via a kanban system, but through an order system. In these cases, an exception had to be made to what was conceptually thought by the project management team. The solution was to make a list of the produced references on paper, using datamatrix codes just as the kanban cards use.
IQ-RM Files
Every FMEA in the plant is made using IQ-RM software and the control plans must be exported directly from this software, ready to be imported by WCPL_MAN without errors. Therefore,
the necessary changes must be done using this software which was not as simple as editing an Excel spreadsheet.
Firstly, it was necessary to find the correct and most recent file and respective work-on, a document that serves as proof that the FMEAs and respective control plans were approved. This was a difficult task due to the current document management of this type of files.
References produced
Since there are, within the same models, references that have different characteristics, it was a requisite that every control should be associated with these references in concrete and not with the models or family these products were part of. Using SAP, a list of references had to be made for each characteristic of each control plan, either by consulting the structure of one product or by consulting which products were made using a certain part (mounted part in that characteristic). This is not as simple as it sounds since there are many part references for each characteristic and it has to be guaranteed that all of them are gathered. If not there will be final references missing and when the user scans the kanban card nothing will show up.
Order Sequence
When the controls were registered by hand, the order of the controls had no impact for the worker. By using a tablet the order of controls the control plan becomes important because the workers are used to a certain order. In order to facilitate the user’s work, paying attention to the order of the controls and changing them was critical.
Special Cases
In section S856 there are five standard gauges, one for each model produced in this section. The process control in the four leakage test station is made at the beginning of every shift to ensure the test equipment is working properly. At the same time this process control also uses the standard parts to confirm that they don’t have leakage ratesout of specification. Since each tightness test takes about 1 minute, it is not possible to test each standard part in each equipment because it would take twenty controls at the beginning of every shift and this would result in a great loss of production time. In order to solve this problem, it was decided to use only one of the standard parts (the one of the model being produced at the beginning of the shift) for each equipment and once a week test every standard part of every model.
These controls were different from the standard in other sections and the software used on the Tablet does not allow for two or more frequencies of control of the same type (as such, it was not possible within the same line of control to have “Shift start” and “once a week” controls). The solution was to separate these lines in four, one of each frequency for each calibrated leak standard (OK and not OK).
Correct station inventory number
This point was not as critical before as it is now, since now there is a link between SAP and the software on the Tablet. Therefore, there must be no mistakes in the stations’ number. In order to solve this problem every station number needed to be confirmed in EQU (an inventory management software) and if that’s the case, correct it, add it to the system or in some cases add the inventory number board to the station.
Control Plans update and fulfillment
Since there are control plans that were created many years ago, they reflect the controls of products no longer being made. Also, controls that could be condensed in only one control plan but are dispersed through many, with tightening torques that do not meet product requirements and specifications or controls using patterns and calibers that are no longer used. These problems create the necessity of constantly updating control plans in order to keep them up-to-date. This project served as an opportunity to update, confirm and in many cases cancel and create control plans.
Reduction in the number of control plans
In Figure 13 it is possible to view an overview of the total reduction in number of control plans and the total number of controls edited and adapted since the beginning of this project.
In the case of a few sections, S852 and S851 CPTs, where there are two identical production cells, the control plans were exactly the same but it was mandatory that every cell had its own control plans. By using the Tablet this is not an issue because it all gets integrated.
Not only in these cases but in the case of almost all control plans made with Excel, it was possible to condensate everything in one. In the case of control plans made using IQ-RM this is not possible in most cases since they are associated with different FMEA analysis.
Improvements in information flow and organization
After the implementation of this project in the sections presented in this dissertation, it is possible for the process engineers and quality responsible to quickly consult all the controls made and results just by accessing the WCPL_MAN in their computer or even WCPL_REG in the Tablet. By using WCPL_MAN application they are able to filter all the controls by section, station, type of control or frequency, among other possibilities.
4.4 Analysis of Surveys
In this sub-chapter it will be presented a survey analysis to gather information about the use of the Tablet in the sections where the project was fully implemented.
In order to obtain feedback and understand the workers’ difficulties, a survey was created with the following five questions:
- Approximately how many times do you think you used the Tablet? - Do you prefer to make controls using the paper sheet or the Tablet?
- Do you waste more time making controls using the paper sheet or the Tablet?
- From your point of view, what are the main problems using the Tablet? Which improvements do you suggest?
- Do you have a leading role in the section?
In total there were 91 surveys fulfilled, by all the persons that make controls in MOE1 (S851, S852, S871 and S855) sections, of all the daily shifts.
As it is possible to see on Figure 14, most of the workers already made more than 20 controls, as it was expected since this project was implemented a few months before the writing of this dissertation in most of the sections.
Figure 14 - Graph of the number of times each worker used the Tablet
As it is possible to see in Figure 15, most of the workers have a preference for the Tablet, despite it taking longer than the registry on the paper sheet (Figure 16).
Figure 15 - Graph of the workers’ preferences Figure 16 - Graph of the workers’ opinion on the control times
It is not a surprise that most of the workers suggest that the registry takes longer on the Tablet. This was expected as part of a learning curve in the use of the Tablet.
Difficulties and suggestions
One of the main difficulties presented was the network failure and consequently slow Tablet functioning.
There were also complaints about the time it takes to get the Tablet or the time lost waiting for colleagues to finish their controls in sections where there is only one Tablet available for everyone.
Finally, it was reported that it is difficult to use the Tablet without taking the protection gloves off and caused the worker to take more time making the controls by taking the gloves off and on.
Data Analysis
For the purposes of this analysis, the users were divided in two groups: the main users of the Tablet, that used the Tablet in at least eleven occasions, and the ones that used it less than eleven.
It was possible to reach the following conclusions:
- The group that uses the Tablet more regularly has preference by it over the ones that don’t.
- 32% of the regular users considers that the registry takes longer with paper sheet than with Tablet and 52% that it takes longer or the same time as with the paper sheet.
Conclusions
The problem of network failure and slow Tablet functioning was a problem the project management has been dealing with since the implementation in the pilot section S855 and are working untiringly to solve.
For the sections where the time of control was an issue more Tablets and drawers were ordered. Also, by proceeding with the installation of a cable wire with a pen on the Tablets, the issue with the gloves was solved.
Although the feedback was positive, there are certainly many improvements to be made. The objective is to continue to work toward facilitating the use of the Tablet for the operations in terms of ergonomics and control time as it collides with production.
5
Conclusions and prospects of future work
During the making of this dissertation the project has been implemented in all the sections of MOE1 and part of MOE4 sections. The objective is to have finished this implementation in the final assembly lines by October 2016 and give support to MOE2 and MOE3 sections in order to finish the implementation of the project by February 2017.
There will also be some side-projects that include the addiction of process parameters to the control plans, continuous software improvement with a better overview of the controlled processes, a control agenda connected to SAP production orders and automatic recording through NTC system, wasting the minimum time for the operator. Also, some time frequencies will be added, which are required for some of the future sections where the project will be implemented.
Another useful purpose for the use of the Tablet will be to take photos of the quality problems directly and send them to the responsible to be analyzed.
In the future, after the implementation of this project in all sections and all the necessary improvements, there will be process analysis using SPC, NTC and Tablet and will be possible to make a statistical control of every process in the plant without requiring much effort or time. This will allow the early detection and prevention of problems, rather than the correction of problems after they have occurred. This system makes it less likely the finished product will need to be reworked.
Finally, this pioneer project at Bosch will be implemented at other Bosch facilities around the world, by using the same software, developed at Bosch Aveiro plant.
This project has been a success, despite all the challenges it has presented over these months. It was conceptually well thought and in my opinion, based on field observations, it will change the paradigm in quality control, by taking advantage of the evolution of the technology world and adapting to the next generation.
This project gave me the opportunity to improve not only my knowledge about the processes and products, as it allowed me to improve my soft-skills, since it was required a lot of communication in order to obtain the information I needed for my work. It also opened up possibilities and allowed me to connect with many different people who taught me part of the knowledge they have gathered over the years. This project has undoubtedly been a great experience and I will be involved in it, after the dissertation period finishes, until its end, when the implementation is concluded in all sections of the plant.
References
Thomas Pyzdek and Roger W. Berger 1991 “Quality Engineering Handbook”, Marcel Dekker, New York.
Walter A. Shewhart 1931, “Economic Control of Quality Of Manufactured Product”, Martino Fine Books, United States
George W. Roberts 1994, “Quality planning, control, and improvement in research and development”, Marcel Dekker, New York.
Armand V. Feigenbaum 1991, “Total Quality Control”, McGraw-Hill, Singapore
Chrysler Corporation, Ford Motor Company, General Motors Corporation 1993, “Potential Failure Mode and Effects Analysis (FMEA)”, Carwin Continuous Ltd. Unit 1 Trade Link, Western Ave, West Thurrock, Grays, Essex, England.
Chrysler Corporation, Ford Motor Company, General Motors Corporation 1994, “Advanced Product Quality Planning and Control Plan (APQP)”, Carwin Continuous Ltd. Unit 1 Trade Link, Western Ave, West Thurrock, Grays, Essex, England.
Taiichi Ohno 1988, “Toyota Production System: Beyond Large-Scale Production”, Productivity Press, United States
Keki R. Bhote 2003, “The Power of Ultimate Six Sigma”, American Management Association, New York
http://www.mobile-qr-codes.org/history-of-qr-codes.html, last access: June 2016
Jeffrey K. Liker and David Meier 2005, “The Toyota Way Fieldbook”, McGraw-Hill, New York
ANNEXE A: Bosch Control Plan
Figure 17 – Bosch Control Plan
Plant
Company and/or appropriate division/plant.
Department
Department responsible for creating or updating the CP.
Prototype/Pre-Launch/Production check-box
Stage of the CP.
Product Description
Description or name of the product, product family or process that the CP describes.
Line
Production/assembly line for which the CP is valid. If it is valid for more than one line, all valid lines must be entered.
Part Number
Part number for which the CP is valid. If it is for a product family, enter all individual products in the Product Matrix.
CP Number
The CP number is to be defined on a local level, but should be defined so as to enable an easy link to the corresponding P-FMEA and other CP versions to be made.
Revision number
Number of the last revision.
IQFMEA Number
FMEA number the CP was based on.
Change date
Date of the current revision.
Date (original)
Date of the first version of each type of control plan was created. For one product family, the prototype, pre-launch and production CPs will each have a different date.
Written By
Name of the author, and later the name of the person who revises the CP
Production Flowchart
Simplified version of the process and test steps in the appropriate order, represented by symbols. All process/test steps and their path must be shown, including rework, variant or alternative processes. Where parts join or leave the process flow, their exit and re-entry points must be shown clearly.
Process Number
Reference number for the process step. Generally, the numbers should start at 1 and be sequential, except where rework or alternative routes are being shown.
Part
Description and/or Name of the part or parts being processed, together with their part numbers (TTNR).
Machine Equipment Tooling
Description of the equipment used to conduct the process step. Should be clear for a non-familiar reader and also identify it precisely. The name and ID number of the equipment, make, model number, asset number etc. must be shown.
When necessary, the workstation number can be given here instead of equipment IDs.
Process Characteristics
Attributes of the process, which are to be controlled in order to ensure the quality of the component or product. They could also be termed input variables, and they have an impact on the resulting product characteristics. These must be set beforehand or controlled/monitored during the production of the part. As such, it is often not possible to check these later after the process is complete, and they cannot be measured on the part (e.g. tightening torques in screws that cannot be measured directly in the product).
The numerical value of the required characteristic is entered along with its description, (e.g. pressure 150mbar). However, this value is given with a tolerance in the column Product/Process specification/tolerance.
Product Characteristics
Attributes of the product/component which must be maintained to ensure the quality of the product. They are often indicated on drawings, product specifications or work instructions. The distinction to process characteristics is that product characteristics can be measured or observed after the process step is complete. They could also be termed output variables. Often the numerical value of the required characteristic is entered along with its description. However, this value is given with a tolerance in the column Product/Process specification/tolerance.
Identification of Special Characteristics
Safety relevant criteria, must be identified in this column with the appropriate symbol. If the customer has another special requirement or any other special feature that should be noted, this must also be included here.
Maintenance Plan
This describes the regular maintenance plan that is in place to ensure the process continues to run as planned. When the plan is written as a procedure with an identification number, this number must be included here.
If TPM activities have been defined, these must also be referred.
Machine Capability
The capability report for the relevant machine or test equipment must be entered here.
Rejection Devices
This describes any devices which will automatically reject a non-conforming part.
For the case where parts are only assembled, and the product characteristics will be tested later in the process, a reference to the test can be placed in this column. The reference must contain the name and CP line number of the corresponding test. In this case, the subsequent columns for the assembly step must not be completed.
Product/Process specification/tolerance
The numerical value of the required process or product characteristic to be controlled is given here, along with the tolerance (e.g. 150 ± 10 mbar). These values are often found on technical drawings, work instructions, specifications, standards etc.
Test Equipment
The equipment used to check or monitor the product or process characteristic is identified and described. In cases where specific equipment is to be used, the ID of the equipment is to be listed. Where multiple equipment can be used, all possible test equipment IDs must be noted here or a reference made to a separate matrix.
Records
Note of where any records of the process or product checks are documented, including document numbers where appropriate.
Test Method (Registration by)
Description of the method used to check the process or product characteristic is within the required tolerances.
The description should be brief but clear enough for someone not familiar with the process. Where available, the appropriate Test Instruction number must be referenced.
Scope
The number of parts that should be checked or the number of repetitions at each interval (e.g. when checking a tightening torque: 5 screwings).
In cases where all parts are to be checked (e.g. 100%), this should be entered here.
Frequency
How often the check of the process or product characteristic should be conducted (e.g. once per shift/week, every 200 parts, reference change).
Reaction Plan
Detailed description of the actions that must take place when a part or process is found out of tolerance/specification, including responsibilities for completing the actions.
If desired, a matrix of standard reactions can be created locally as a separate document. The individual lines in this column can then reference this reaction plan matrix.
