Every design process begins by identifying and analyzing the need, and defining it in terms of the design requirements. Clarifying and quantifying the design task helps the designer to gain crucial insights that will facilitate the creation of innovative products. This chapter provides a methodology for carrying out these initial steps. The methodology first calls for identifying the real need in qualitative and solution-independent terms. Next, the overall need is studied in light of five basic categories of functions and constraints: performance, value, size, safety, and special. These functions and constraints should be fulfilled and satisfied by any design solution that will emerge later in the design process, yet any premature specification of design solutions is carefully avoided during this stage. The need analysis is summarized at the end of the process as a consistent and quantitative set of design requirements.

The Importance of Need Identification

Design tasks arise from a variety of sources, sometimes referred to as “customers.” Because these sources are often nontechnical, the tasks may not be defined in engineering terms. Furthermore, initial task statements sometimes describe perceived problems as opposed to real needs. The natural tendency of novice designers is to start thinking of solutions that satisfy the perceived problem before gaining full understanding of what should really be designed. This tendency, coupled with a lack of proper definition of the task, may mislead the designer and waste his or her time and effort in solving the wrong problem.