Reliability Engineering

6Product Requirements and Constraints

Product development is a process in which the perceived need for a product leads to the definition of requirements that are translated into a design. The definition of requirements is directly derived from the needs of the market and the constraints in producing the product.

6.1 Defining Requirements

One of the first steps in product development is the process of transforming broad goals and vague concepts into realizable, concrete requirements. While the company's core competencies, cultures, goals, and customers all influence the requirements, Figure 6.1 shows that the product definition results from a combination of marketing and business-driven product requirements, design and manufacturing constraints, and various external influences.

Figure 6.1    Example requirements and constraints in the product definition process.

Marketing often takes the lead in determining requirements for products such as toys, cell phones, and personal computers. For components of more complex products (e.g., an engine control module for an automobile), the requirements and constraints are often defined by the customer (the manufacturer of the product or system that the component fits into), and the marketing function is less involved.

The development of product specifications begins with an initial set of objectives, which are formulated into a preliminary requirements ...