Customer needs are generally expres

Customer needs are generally expressed in the "language of the customer." In order to provide specific guidance about how to design and engineer a product, development teams establish a set of specifications, which spell out in precise, measurable detail what the product has to do to be commercially successful. The specifications must reflect the customer needs, differentiate the product from the competitive products, and be techni­ cally and economically realizable.

• Specifications are typically established at least twice. Immed i ately after identifying the customer needs, the team sets target specifications. After concept selection and testing, the team develops.f!na/ specifications.

• Target specifications represent the hopes and aspirations of the team, but they are es­ tablished before the team knows the constraints the product technology will place on what can be achieved. The team's efforts may fail to meet some of these specifications and may exceed others, depending on the details of the product concept the team even­ tually selects.
• The process of establishing the target specifications entails four steps:

I. Prepare the list of metrics.
2. Collect competitive benchmarking information.
3. Set ideal and marginally acceptable target values.
4. Reflect on the results and the process.

• Final specifications are developed by assessing the actual technological constraints and the expected production costs using analytical and physical models. During this refine­ ment phase the team must make difficult trade-offs among various desirable character­ isti cs of the product.
• The five-step process for refining the specifications is:

I. Develop technical model s of the product.
2. Develop a cost model of the product.
3. Refine the specifications, making trade-offs where necessary.
4. Flow down the specifications as appropriate.
5. Reflect on the results and the process.

• The specifications process is facilitated by several simple information systems that can easily be created using conventional spreadsheet software. Tools such as the list of metrics, the needs-metrics matrix, the competitive benchmarking charts, and the com­ petitive maps all support the team's decision making by prov iding the team with a way to represent and discuss the specifications.
• Because of the need to utilize the best possible knowledge of the market, the custom­ ers, the core product technology, and the cost implications of design alternatives, the specifications process requires active participation from team members representing the marketing, design, and manufacturing functions of the enterprise.