Utveckling av arbetsmetod för DFA
Scania is among the leading companies in the heavy vehicle industry. Scania also assemble engines for their trucks and buses, as well as to external marine and industrial applications. Wrongly assembled parts leads to quality problems, which makes it important to secure that the assembly is correct. To do this Design For Assembly (DFA) is used to describe how parts should become easier to assemble. Scania?s production unit for engine assembly has had a working method for DFA in the shape of a checklist, which is not used. The goal in this project was to investigate why the method is not used and to give suggestions for improvements.The problem with the existing DFA-method and the reasons it was not used was investigated through interviews and observations. A literature review was done to study other, established DFA-methods. Other production units at Scania were looked into as well, to compare their working approach towards DFA.Many rounds of tests were conducted to improve the DFA-method. The tests were applications to real cases. One problem was that the checklist was too complicated. The result was a modified checklist in which the number of questions went from 45 in the original to 24 in the final version. New response levels were introduced containing decision-making responses in a combination with points for the ability to measure and compare different DFA-analyses. The questions were organised into three main areas: product questions, assembly questions and remaining questions.In accordance to how other production units at Scania works with DFA, a new method, parallel to the checklist, was created to visualise easy assembled engine parts through the revision of an old. The old method contained articles with descriptions of good solutions regarding assembly. Using an internal Wikipedia system links were created between these articles to be able to reach all of them through three main categories: the DFA-technique is known, the product category is known or going through the subsystems in the engine?s design structure.A simple implementation plan was developed to recommend an implementation of the working method. Suggestions for further improvements when working using the method were given as well. An important improvement area was to find out where in the development process the DFA-method should be used.