Integrate Ergonomics into Production System Design

A case study is presented evaluating the productivity and ergonomic consequences ofstrategies implemented in a re-design of an electronics assembly system. The companyapplied partial automation strategies for assembly and transportation functions, movingfrom a parallel-batch to a serial line-based production system. Through simultaneousconsideration of technical and ergonomic indicators we aimed to identify linkagesbetween design decisions, productivity, and ergonomics. Data obtained from companyrecords and key company informants were combined with detailed video analysis,biomechanical modelling and field observations of the system. Implementation of thestrategy to partly automate assembly operations was seen to reduce labour inputs forcomponent assembly work without directly affecting ergonomic conditions. The automation of transportation strategy reduced both labour inputs and work in progress.This strategy also resulted in considerable reductions in work-task variability, and henceincreases in repetitiveness for operators at manual assembly workstations. The manualassembly station examined had some increase in shoulder load amplitudes and a largerincrease in the time-density of work (reduced porosity). Work activities were focusedalmost exclusively on stereotyped ‘get and put’ actions which increased in averagefrequency from one every 8.3 seconds to one every 7.4 seconds. Workstation design wasconstrained by initial decisions to adopt automation technologies and also affected bylater problems in the automation of assembly. Ergonomic conditions varied acrossindividuals and stations in the system. The adopted work organisation plan resulted inuneven distribution of risk factors across operators in the production system. It isconcluded that strategic decisions made early in the design of the production system haveconsiderable impact on ergonomic conditions in the production system. Optimal designfor sustainable and efficient production require simultaneous and integrated considerationof technological and operator functions in the manufacturing system.