Design for life cycle refers to the product after it has been manufactured. In many cases, a product can involve a significant cost to the customer beyond the purchase price. These costs include installation, maintenance and repair, spare parts, future upgrading of the product, safety during operation, and disposition of the product at the end of its useful life. Table 8.3 lists most of the factors associated with life cycle design of the product.
The cost of a product is a major factor in determining its commercial success. Cost affects the price charged for the product and the profit made on it. Design for product cost refers to the efforts of a company to identify the impact of design decisions on overall product costs and to control those costs through optimal design. Many of the DFM guidelines are directed at reducing product costs. It is often useful for a company to develop a product cost model to predict how design alternatives might affect costs of materials, manufacturing, and inspection.
Table 8.3 Factors in design for life cycle.
Source: Adapted from Groover (1999).
| Factor | Typical issues and concerns |
| Delivery | Transport cost, time to deliver, storage and distribution of mass produced items, type of carrier required (truck, railway, air transport) |
| Installability | Utility requirements (electric power, air pressure, and others), construction costs, field assembly, support during installation |
| Reliability | Service life of product, failure rate, reliability testing requirements, materials used in the product, tolerances |
| Maintainability | Design modularity, types of fasteners used in assembly, preventive maintenance requirements, ease of serving by customer |
| Serviceability | Product complexity, diagnostics techniques, training of field service staff, access to internal working of product, tools required, availability of spare parts |
| Human factors | Ease and convenience of use, complexity of controls, potential hazards, risk of injuries during operation |
| Upgradeability | Compatibility of current design with future modules and software, cost of upgrades |
| Disposability | Materials used in the product, recycling of components, waste hazards |
To the customer, the price paid for the product may be a small portion of its total cost when life cycle costs (LCCs) are included. Some customers (e.g. the federal government) consider LCCs in purchasing decisions. The manufacturing must often include service contracts that limit customer vulnerability to out‐of‐control maintenance and service costs. Here, accurate estimates of these LCCs must be included in the total product cost (Groover 1999).
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