Dimensional management or geometry assurance is an engineering methodology where the production process prerequisites are integrated into product engineering.
The dimensional management process starts at styling and concept creation where the product targets are set. The process ends after verification of targets during pre-series production.
Dimensional variation can not be eliminated but the variation outcome can be reduced and controlled through optimal selection of part datums, feature controls and process steering attributes.
By reduction of factors in tolerance chains and calculation or computer-simulation of chain contributors the real variance outcome can be predicted virtually.
This method improves quality though unambiguous and realistic requirement definition and reduces cost through "robust design" with less dimensional variation.
Scope of services:
- Dimensional management services include dimensional assurance and tolerance management for a new product through the whole development process.
- The main phases of dimensional management are:
- Target definition
- Engineering and manufacturing process variance optimization
- Tolerance definition
- Variance verification
- Production release
- The specific activities are for instance:
- Evaluation of styling proposal with regard to tolerance variation and functionality aspects
- Target assessment regarding visual outlook, fit and function
- Definition of "datums" and process steering elements for improved part positioning
- Optimization of part positioning for automated or manual assembly process
- Virtual tolerance verification analysis of engineering ideas and concepts
- Definition and documentation of tolerance parameters
- Verification of tolerance variation outcome based on product and process measurement data
- Specification and optimization of measurement needs for components and assemblies
- Supplier support for dimensional and tolerance target fulfillment
- Tolerance verification and analysis during a physical Cubing/Nominal Buck process
- Problem solving by root cause analysis and reduction of unwanted and disturbing tolerance outcome.