Assessment and Improvement of Final Assembly Processes for Complex Highly Engineered Mechanical Systems
Open Access
- Author:
- Tosta Otamendi, Pablo Esteban
- Graduate Program:
- Industrial Engineering
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- None
- Committee Members:
- Robert Carl Voigt, Thesis Advisor/Co-Advisor
Paul Carl Lynch, Thesis Advisor/Co-Advisor - Keywords:
- Labor utilization
assembly
throughput
lean manufacturing
six sigma
interaction map
continuous improvement
workforce
oil. - Abstract:
- This research project focuses on the complex, highly engineered mechanical systems of final assembly process of the BOP stacks. It was developed using data from one of the largest facilities of an oil rig solutions manufacturer. The components that are manufactured in this facility are used in the drilling and extraction operations of oil wells. This thesis includes construction of process flows, inter and intra-departmental information flows, cause and effect diagrams, Six Sigma SIPOC diagrams and interaction maps, as the initial phase of a project followed by a high level overview of the processes previous to final assembly. Furthermore, detailed construction of assembly timelines (histograms) using three conventional stack projects and four configurable stack projects were developed. The last four projects were used to develop four different assembly scenarios to present simulated solutions of workforce allocation and labor utilization concerns as a means to increase overall throughput at the stack pad. Assuming no delays cause by pre-assembly processes, calculations of the average available man hours, minimum achievable times for each assembly operation and a vetting process of all the results, stack pad throughput was calculated for the last three scenarios considering different labor utilizations. The first scenario was developed as an ideal approach using a Gantt chart simulation criterion where total touch and idle/wait times were calculated and compared with standard times for a precedence constraint manufacturing process with no delays. After developing the assembly labor utilization scenarios, it was found that variations in labor capacity have a big impact in stack pad throughput. As a consequence, considerations have to be made to labor scheduling in order to lower costs by optimizing the labor allocation at any given point in time. In addition, many considerations have to be taken into account to eliminate the no delay assumptions and consider different strategies to develop a no delay report system and root cause analyses procedures to address the relevant issues affecting final assembly.