Ergonomics in parallelized car assembly: a case study, with reference also to productivity aspects

Changing from batch to flow assembly in the production of emergency lighting devices

“…Because of this, the number of subjects that was required was limited. Nevertheless, we consider the number of subjects that we could have in this company as rather low (although the numbers in other studies on ergonomic effects are quite similar or even lower; Kadefors et al 1996. Despite the low number of subjects, however, we were able to observe a significant effect on the arm elevation and on the level of experienced fatigue.…”

Are changes in mechanical exposure and musculoskeletal health good performance indicators for primary interventions?

“…In nine out of 12 studies (75%) with quantification of mechanical exposure a reduction of 14%-87% was observed, which was statistically significant in eight out of nine studies (89%). In these 12 studies, eight (67%) also showed a reduced prevalence of musculoskeletal symptoms or reduced sick leave due to WRMSD (Aara˚s 1994;Aara˚s et al 1998;Brisson et al 1999;Garg and Owen 1992;Kadefors et al 1996;Lewis et al 2001;Reynolds et al 1994;Wickstro¨m et al 1993).…”

“…In addition, there were three randomised controlled trails Gundewall et al 1993;Poppel et al 1998), three cross-sectional studies (Hinnen et al 1992;Johansson et al 1993;Kadefors et al 1996) and seven longitudinal studies (Aara˚s 1994;Bernacki et al 1999;Chatterjee 1992;Fredriksson et al 2001;Lagerstro¨m et al 1998;McKenzie et al 1985;Wickstro¨m et al 1993). Of the 34 studies using a prepost or longitudinal design, only 13 studies (38%) used a control group (Aara˚s et al 1998;Brisson et al 1999;Feldstein et al 1993;Fredriksson et al 2001;Leclerc et al 1997;Perkio¨-Ma¨kela¨and Riihima¨ki 1997;Shi 1993;Silverstein et al 1988;Thomas et al 1993;Videman et al 1989;Vink et al 1995;Wickstro¨m et al 1993;Wood 1987).…”

“…Work places and work organisations are continuously liable to changes that may interfere with the effects of the intervention. An extreme example is the intervention study by Kadefors et al (1996). Nevertheless a successful intervention programme, the intervention sustainability was poor, since the factory was closed shortly after the study.…”

Integrating human factors into discrete event simulations of parallel flow strategies

“…MSDs, unlike accidents, can emerge from the normal operation of the production system and are caused by both physical factors, such as repetitive work or vibration, as well as psychosocial factors such as job autonomy or co-worker support (Bongers et al 1993, Hagberg et al 1995, Karasek et al 1998, National Research Council 2001. Case study research has illustrated how specific system design features, such as flow strategy, automation use and work organisation, can influence the operators' physical and psychosocial demands at work (Berggren and Rehder 1994, Engstro¨m et al 1995, Kadefors et al 1996, Melin et al 1999, Neumann et al 2002, Kihlberg et al 2005, Neumann et al 2006, Kazmierczak et al 2007). Thus the production system designer is determining injury risk for operators even at early decision points in the design process -choices that can be too expensive to correct in operational systems.…”