Ergonomic Improvements : A Case Study in the Production of Red Dot Sights

This thesis of 30 HP is the final part of the program Master of Science in Industrial Design Engineering at Luleå University of Technology, performed during the spring of 2016. The work has been performed at Aimpoint in Malmö, Sweden, who are world leading in the production of red dot sights for military and hunting applications. The company in Malmö consisted at the time of this thesis of about 110 employees, whereof 62 assemblers in the production. The production consisted of a cleanroom and packaging unit. Due to former work related injuries among the assemblers in the production, the objective of this thesis has been to investigate which workstations that could be straining on the body, and which body parts that were affected. With this information some suggestions for improvements through an ergonomic perspective regarding work environment and working postures were developed. The aim of this thesis has thereby been to lower the work-related injuries by improving the work environment.The red dot sight that is assembled by hand at Aimpoint comes in three main assembly families, called Hunter, Comp and Micro, which can be divided into Micro 1 and Micro 2. These three families are preassembled along 16 workstations before they enter their own line consisting of five workstations, all stationed in the Cleanroom. When the sights are assembled, these are sent for laser marking and packaging in the packaging area. The theoretical background of this thesis concerning ergonomic guidelines, common work related injuries, long-term sitting, the salary and Lean Production’s affection on the body, contributed to a good foundation of this project. Through a questionnaire and interviews, information could be gained about the workload in the production from the assembler’s point of view. From further methods such as HTA, RULA, OCRA and observations, a clear picture of which workstations that were containing repetitive, straining and strengthening working postures was established.The results showed that the second station of Comp, the electronics mounting on Micro and the cleansing of all sights, all situated in the cleanroom was classified as most straining for the wrist. For the neck and back the cleansing, collimation of Micro 2 and the final assembling were the most straining. In the packaging area, the results indicated that the occurring working posture by placing the sights in the laser machine was damaging to the neck and back. The fatigue in the wrist emerged as a problem by the mounting of accessories of Comp and the removing of lens covers from returned sights. Generally, in both production areas was most of the work performed with bent necks, backs and wrists, in order to be able to see and handle the small components. The assemblers did also perceive the work as stressful sometimes with high demands but with low decision space. The main issues that were discovered as reasons for straining injuries on the body gave a decent ground for the suggestions of improvements that were developed through brainstorming and online benchmarking. Examples of appropriate solutions were restructuring of the instruments, better support for the arms, better lighting, height adjustable fixtures and ergonomic educations. While the production technicians and the improvement groups constantly are working with implementing helping tools, a document for an easier evaluation of these tools was established.Validerat; 20160707 (global_studentproject_submitter