Product Evaluation

Product Life Cycle

Typically, product development travels a path from initial conception or high-level design through detail design, manufacturing, marketing and sales, postsales warranty and support, to retirement. Evaluation priorities, methods, and, indeed, the meaning of the term product evaluation change during this life cycle.

Early in the product life cycle, evaluation is an exercise in requirements analysis. Requirements are multidimensional and typically include user need, manufacturing capacity, produceability, production cost, regulatory compliance, timing of market entry, sales volume, and the relationship of a product to an entire product line. Evaluation at this stage requires assessment of both individual requirements and the overall fit of the product within a multidimensional “requirements space.” Getting it right is important because the downstream consequences of wrong decisions can be extremely damaging.

Evaluation at the detail design stage focuses on whether the product development process is meeting its targets for time, cost, and functionality. However, the essential question is not whether individual milestones for individual components are met, because design is not just a cumulative function of activities that have invariant, well-defined relationships. Rather, product development is best seen as a nonlinear open system, complete with unanticipated environmental [Page 329]change (e.g., business climate, user needs); sensitive, cascading consequences among large and small perturbations; unpredictable dependencies among different design activities; and emergent behavior that makes it difficult to specify “part-whole” relationships. Although monitoring individual budget and milestone activity is critical, it is also critical to address the big evaluation question; that is, in the face of inevitable change, is the design process adaptable enough to meet overall targets for cost, production schedules, and functionality?

During manufacturing, evaluation should assess both the product itself and the process by which the product is manufactured. Both are important in understanding why a product behaves as it does. Typical process measures include throughput, quality, manufacturing cost, machine behavior, and achievement of production schedules. Metrics are indicators of the fit between the finished product and its design and performance specifications. The importance of evaluating both product and process often goes beyond a simple desire to cover all relevant issues. Rather, it is often the case that a specialized manufacturing process is needed to create a particular product, and in such cases, the distinction between “product” and “process” is false because understanding one requires understanding of the other. An indicator of the link between product and process lies in the choice of methodology for product evaluation. One possibility is to measure the product after it is produced. Another is to use a well-proven manufacturing process and to make sure that the process meets its performance specifications.

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