The Use of Process Capability Data in Design
When a design is created, the designer specifies the geometry, dimensions, and material of the parts. This information is used to tell manufacturing how to produce the parts. In addition, the designer specifies tolerances, which are used to guide the process selection and parts acceptance. Acceptability can be determined in a number of ways, including process validation and inspection.
Traditionally, the process of tolerance specification has been unidirectional; i.e., the design specifies the tolerances, and manufacturing is expected to meet them. However, in the new paradigm of design for manufacturing and concurrent engineering, communication with manufacturing is necessary to ensure that the tolerances specified are consistent with manufacturing’s capability. By ensuring producibility before a design is released to manufacturing, expensive redesign, processes, rework, and customer dissatisfaction can be avoided.
This chapter was designed to help planning a process capability database implementation. It is based the author’ s experience with implementing process capability databases in a number of large manufacturing/design organizations. The chapter starts by reviewing the typical data content and structures. Next, the chapter reviews the issues of using surrogate data. The final section discusses implementation issues.
KeywordsProcess Capability Statistical Process Control Surrogate Data Indexing Scheme Concurrent Engineering
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