Förbättringsarbete för att minimera andelen metaller i fragmenteringsrester: En fallstudie enligt DMAIC vid Stena Recyclings fragmenteringsanläggning i Hallstahammar
Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
If the world’s natural resources should cover future needs one obvious solution is to recycle more to decrease the extraction of primary resources. The car industry is one of the most resource intensive industries for ferrous and non-ferrous metals and the need for resources is growing. Environmental concerns for the effects of end-of-life vehicles have led to legislation with the target of a recycling degree of 95 % of the cars´ mass in 2015. This target was not achieved and substantial efforts are still required to reach this target.The metal recycling industry is viewed as one of the most important areas for improvements within the whole recycling industry because recycled metal has the same characteristics as newly produced metal. To make the metal recycling industry more resource efficient improvement work that has strong focus on reducing variation is required. The problem solving methodology DMAIC popularized within Six Sigma has been described as the leading approach to tackle variation problems without obvious solutions. DMAIC methodology is based on a structured and fact based improvement approach. The lack of previous studies of Six Sigma in the metal recycling industry leaves the need for good examples to illustrate the approach and the potential benefits.In this thesis a DMAIC project at Stena Recycling’s fragmentation plant in Hallstahammar has been performed to apply and illustrate how DMAIC methodology can work in the metal recycling industry. A secondary purpose was to provide recommendations for a continued implementation of Six Sigma in the organization. However, the fragmentation residues that end up in landfills still contain a large amount of metals. The purpose of the DMAIC project was to minimize metals in the fragmentation residues. An additional purpose of the DMAIC project was to provide recommendations of how to use of statistical data to monitor and reduce variation. The lack of secondary data of potential causes to why metals end up as fragmentation residues meant that data collection mainly was based on primary data.The DMAIC project resulted in a decreased waste in fragmentation residues earning savings of 294 000 SEK per year as well as a number of suggestions for improvements for on-line monitoring and reduction of variation. These suggestions are primarily focused on the use of statistical control charts and a focus on following guiding measurements that can be influenced by operators.If Stena Recycling chooses to continue with implementing Six Sigma in the organization they are assessed to have good possibilities for internal recruitment of Six Sigma competence. The need for support functions is substantial if the person responsible for improvements lacks prior experience of managing DMAIC projects. Six Sigma is based on frequent use of statistical tools and therefore requires access to measurement data. Stena Recycling’s greatest problem today concerns the currently limited measurement system. If differences caused by adjusted settings cannot be detected and monitored, the motivation to actively work with improving the processes will suffer.Based on the result the DMAIC methodology is regarded as a suitable approach for reducing variation in the metal recycling industry. DMAIC methodology has previously been applied successfully in a variety of industries and the results from this DMAIC project demonstrate its high degree of generalizability.
Place, publisher, year, edition, pages
2016. , 74 p.
Social Behaviour Law
Samhälls-, beteendevetenskap, juridik, Sex Sigma, DMAIC, metallåtervinning, fragmenteringsrester
IdentifiersURN: urn:nbn:se:ltu:diva-42378Local ID: 063e1c4b-0910-49cc-aabb-a8a16fc0cd1bOAI: oai:DiVA.org:ltu-42378DiVA: diva2:1015598
Subject / course
Student thesis, at least 30 credits
Industrial and Management Engineering, master's level
Validerat; 20160612 (global_studentproject_submitter)2016-10-042016-10-04Bibliographically approved