A stage consists of a set of parallel activities. Completing the activities produces a set of work products. Work products can be calculations, estimations or information. An example of a work product is an estimation of the size of the market or the cost of the product. Successive stages are separated by decision points called gates, which provide objective criteria and rubrics to assess the project. Management uses these criterion to decide if the next stage should be funded. Figure 2 shows a stage-gate pair.
A decision must be made at each gate. The limited number of possible outcomes are shown below
- The project can move on to the next stage
- The project can be ended if the information compiled in the stage shows that the project is not feasible.
- Some modules in the stage can be re-done if more or better information is required to make a decision.
The stage-gate model can be deployed to describe the product design process. Each stage is broken into modules. When completed each module yields work products that are evaluated at the next gate. Each gate contains a rubric of criteria that will allow you to determine if you are ready to take the project to the next stage.
We will use the following stages to represent the product design process.
- Opportunity Creation
- Business Concept
- Customer Needs
- Engineering Concepts
- Refine, Evaluate and Select
- Generating Conceptual Designs
- Design Verification
- Detail Design