An Investigation of Mura and Muda in Large Aerospace Development Projects Open Access
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The elimination of waste is essential to efficient production in any industry. While the concept of Lean has been examined in tandem with engineering and aerospace projects, Lean’s foundation in manufacturing has limited much of the related research to that particular industry; scholars had yet to examine the release of engineering drawings for large aerospace development projects from a Lean perspective. This study consisted of two phases aimed at exploring the effects of unevenness in workflow and program organization on the rates revisions required for engineering drawings leading up to CDR. Data were obtained for two large aerospace divisions consisting of three programs and a total of 20 unique builds for a project. The researcher hypothesized that mura, defined as changes in the number of monthly engineering drawings released, was associated with muda, defined as an increase in the likelihood that drawings would require revision. The controlled variables included product type (satellite or launch vehicle) and the customer, which resulted in similarities in management and reporting styles for the two divisions included. The independent variable for Phase 1 was the number of drawings released per month, while the dependent variable was the number of drawings that required subsequent revision. For Phase 2, the dependent variable was the number of revisions per drawing. Analysis for Phase 1 indicated that no significant relationship existed between the number of drawings released per month and the likelihood that a drawing would require revision. Because findings for the first research question were surprising, the researcher expanded the study. The second phase of the study aimed at investigating the possible ways that differences in division organization might contribute to differences in revision rates. The analysis for Phase 2 indicated a statistically significant difference existed in the average revision count between Division 1 and Division 2. Implications of these findings are discussed.