Mapping and analysing manufacturing processes

Abstract

In this thesis, two manufacturing processes used to produce the same bearing bush were mapped and analysed at Oy Johnson Metall Finland Ab. The goal for this thesis was to produce visual representations of the manufacturing process’s workflow, attributes and the capability to produce quality. The thesis was implemented by examining the currently used manufacturing process and an alternative manufacturing process by using flowcharts, value analyses, value stream maps and SPC. The need for the mapping and analysing came from the company’s desire to improve the currently used manufacturing process.

The mapping and analysing revealed that both manufacturing processes had strengths over each other when they were compared together. The currently used manufacturing process had an ability to produce cast faster, but the machining phase required more time. The alternative manufacturing process included more value adding activities and fewer required stages in producing the bearing bush. The SPC study did reveal that there were small differences on quality, but this had no significant impact on the overall quality. The only distinctions noticed quality wise were minor variations in the measuring results that were caused by adjustments made at the lathe during the machining.

Based on the results of the thesis, two suggestions were made for follow-up actions. If the company is willing, a new SPC study could be made for the manufacturing processes in which no adjustments would be made on the lathes during the machining phase. By doing this, actual data on how the machining parameters act during the machining would be gained. The company could also adapt Six Sigma as a part of its organization. Six Sigma would not only reduce the variation inside the bearing bushes manufacturing process, but in all the other processes the company uses.

In this thesis, two manufacturing processes used to produce the same bearing bush were mapped and analysed at Oy Johnson Metall Finland Ab. The goal for this thesis was to produce visual representations of the manufacturing process’s workflow, attributes and the capability to produce quality. The thesis was implemented by examining the currently used manufacturing process and an alternative manufacturing process by using flowcharts, value analyses, value stream maps and SPC. The need for the mapping and analysing came from the company’s desire to improve the currently used manufacturing process.

The mapping and analysing revealed that both manufacturing processes had strengths over each other when they were compared together. The currently used manufacturing process had an ability to produce cast faster, but the machining phase required more time. The alternative manufacturing process included more value adding activities and fewer required stages in producing the bearing bush. The SPC study did reveal that there were small differences on quality, but this had no significant impact on the overall quality. The only distinctions noticed quality wise were minor variations in the measuring results that were caused by adjustments made at the lathe during the machining.

Based on the results of the thesis, two suggestions were made for follow-up actions. If the company is willing, a new SPC study could be made for the manufacturing processes in which no adjustments would be made on the lathes during the machining phase. By doing this, actual data on how the machining parameters act during the machining would be gained. The company could also adapt Six Sigma as a part of its organization. Six Sigma would not only reduce the variation inside the bearing bushes manufacturing process, but in all the other processes the company uses.