The usage of a system engineering approach for integrating machining constraints in the upstream design stage

Abstract

In the early design stage, designers with narrow knowledge of machining would produce a rough part design with arbitrary geometry. This leads to iterative loops between designers and manufacturing engineers when evaluating the manufacturability of a part belonging to a complex system. To overcome this issue, the introduction of set based concurrent engineering approach, built on SysML diagrams with machining constraints in the upstream design stage is induced. This approach will decrease the loops between engineers, and lessen the lead time. This paper presents an advanced approach based on SysML diagrams. First, it will highlight the characteristics of each machining feature of an automotive part belonging to the air conditioning system (dimensions, geometrical constraints and surface roughness), then it will point out other constraints related to production system such as cutting and machine tools constraints. Later, machining operations corresponding to each feature must be classified at a certain order according to precedence relationship or anteriorities based on technical or economical restraints. At this phase, a machining expert must intervene to settle the order of execution which belongs to individual operation. This will bring out many sequencing solutions. Lastly each of the previous solutions must be bonded to its specific lead time and production cost. A case study concerning an electronic throttle body will be posed to illustrate various stages of this concurrent engineering approach.