Producibility of the product family

According to Torvinen et al. (2003), the concept of producibility of a product family in- cludes the aspects of manufacturability, assemblability and many additional aspects. Ac- cording to their definition, producibility of a product includes the following aspects:

• Purchaseability of materials, components, parts and modules

• Material’s ability to be manufactured, formed etc.

• Manufacturability of a part, module and product

• Assemblability of a product, module or subassembly

• Configurability and modularity

• Measurability

• Testability

• Inspectability

• Packageability

• Installability

• Disassemblability of a product, module or subassembly

• Recycleability or a product, module or subassembly

While companies are facing increasing challenges to satisfy customer needs, designing for producibility offers means to avoid disturbance due to the customer specific, configured products (Torvinen et al. 2004). The idea is to integrate production and product design to be able to offer enough product variants and at the same time to make efficient production of configured products possible. This thesis is considering producibility through modularity and configurability. While Torvinen et al. (2003) concentrate on developing products that can be efficiently produced, Lapinleimu offers an idea of an ideal product for an ideal pro- duction (Figure 19).

Figure 19. An ideal product for an ideal production (Lapinleimu 2000)

As shown in Figure 19, modularity acts as the center for a product as well as for the pro- duction system, i.e. modularity offers means to use module-based production. In Figure 19 the idea that there needs to be enough similarity between the product structure and produc- tion system, while simultaneously enabling configurable products, is clarified.

This thesis is considering producibility in the context of configurability and modularity. As mentioned before, the aim is to provide a modular product that satisfies the requirements of production and sales simultaneously. Thus, configurability and similarity between produc- tion and product structure needs to be solved. This provides a producible product structure.

When considering the evolution model presented by Lehtonen (2003), producibility can be seen in relation to configurability and modularity.

Torvinen et al. (2004) see that poor producibility will increase the instability of the system.

Producibility is considered to be the property of a product supporting production system (Lapinleimu 2000). Thus, producibility of the product is offered to provide minimal amount of deviation to the production system caused by the product itself. According to Torvinen et al. (2004), “…new product drawings, new instructions, new tooling etc. can cause instabil- ity. Everything that is new requires a learning process that ‘disturbs’ the system…” The integration between production and product development becomes important. Jensen and Hildre (2004) argue that there are shortcomings in modularization methods when consider- ing manufacturing. The concept of producibility and model provided by Torvinen et al.

(2004) provides insights into this area holistically. Torvinen et al. (2004) present the CSD model (Collective System Design) to provide a holistical view of production system and the importance of product to the production system simultaneously. For example, producibility

PRODUCTION PRODUCT

MODULARITY

COMPILING MAIN PROCESS CELL BASED

PRODUCTION

CUSTOMER NEEDS CONFIGURAB

ILITY

is heavily considered by Torvinen et al. (2004) because the system needs predictable out- puts and producible products provide these outputs.

Torvinen et al. (2004) consider product design and production system in a way that product design provides a product that supports the production system in a way that stability is reached. Torvinen et al. (2004) conclude: “Product design for producibility encompasses topics such as architectural design, detailed design (including DFMA (Design for Manufac- turing and Assembly)), process and flow planning, and operations planning. When the foundation for the stable manufacturing system has been laid with the help of highly pro- ducible products, the goal of the CSD framework proceeds with ensuring the existence of standardized high quality work to minimize all undesired deviations…”. Thus, they provide a well defined framework for integrating product design with production.

Delayed differentiation (Ulrich and Eppinger 2000, Selladurai 2004, Partanen and Haa- pasalo 2004) can also be considered as part of producibility. Modularity offers means for delayed differentiation when designed properly into the product. Delayed differentiation and mass customization are often related. Partanen and Haapasalo (2004) see that require- ment for rapid response manufacturing (Suri 1998) and fast delivery of configured products can be satisfied with modularity and standardized methods. Also Selladurai (2004) sees that process standardization enables mass customization, thus modularity provides means to of- fer pull systems (Pine 1993, Torvinen 2004) next to the use of push systems (MRP, Mate- rial Requirement Planning) through delayed differentiation. The types of modules in modu- lar systems either enable or disable the use of delayed differentiation.

2.5.1. Closing producibility of the product family

This thesis is concentrating on producibility of a product family especially using the aspects of configurability and modularity of product structures. Increasing needs to satisfy cus- tomer needs affect the entire organization while configurable products are one way to pro- vide customer specific product individuals. Modularity is often offered as means to handle complexity and to enable efficient use of configurable products. Simultaneously with con- figurability there are needs to have producible products, i.e. the product structures should be in accordance with the production system. Configurability and similarity between pro- duction system and product structure represent usually different types of modularity, i.e.

functional or structural modularity respectively.

Connecting these ideas to the evolution model of modularity (Lehtonen 2003) and configu- ration matrices, a systematic way of developing modularity can be established. Considering producibility, it is possible to see modularity as means to develop producible products while ensuring the aspect of configurability, i.e. modularity needs to be seen broadly in or- der to eliminate sub-optimizing the product structure.

3. CONFIGURATION MATRICES AND THE IMPLICATIONS TO