Design for manufacture through fabrication : a manufacturing time and cost estimation model for large fabricated assemblies

[摘要] ENGLISH ABSTRACT:This thesis concerns the development of manufacturing time and cost estimationmodels for large mechanical engineering assemblies. The objective of the time andcost models are to serve the design engineer as a tool for estimating manufacturingtime and cost, as the design progresses from the conceptual to the detail design stage.The manufacturing time and cost estimation models will give the designer theadvantage of evaluating different concepts with time and cost as decision makingcriteria. The models can also be used as a redesign tool for existing products so that acost comparison can be made between the existing and new design. The models canalso be used as a design optimisation tool for the manufacturing time and cost of anew design or redesign. This will reduce unnecessary costs associated with a certaindesignBasic process flow diagrams were determined from shop floor practice for eachmanufacturing process and its secondary process( es). Data for these models wereobtained by time studies. The time study data was then used to investigatecorrelation's between manufacturing time and certain design parameters.Manufacturing time estimation formulae were then developed from the time studydata.Five major time and cost estimation models were developed and tested. The fivemodels are: Welding Time Estimation for the Flux Core Arc Welding Process, TackWelding Time Estimation, CNC Flame Profile Cutting Time Estimation, Manual andMechanised Bevelling Time Estimation and Plate Bending Time Estimation. Eachmodel depicts the manufacturing time and consumable requirements.

[发布机构] Stellenbosch University