Degree Type

Creative Component

Semester of Graduation

Summer 2021


Industrial and Manufacturing Systems Engineering

First Major Professor

David Sly

Second Major Professor

Guiping Hu


Master of Science (MS)


Industrial Engineering


This case study focuses on Dethmers Manufacturing Company (DEMCO), located at Spencer, Iowa, where they manufacture semi-trailers. Their semi-trailer sales have rocketed up to a 200% increase compared to last year. Offering diverse model options (over 45 different models and 500 different options) without standard operating procedures, the operators have a hard time understanding the process and assembly. This leads to an exponential increase in the overall lead time and creates bottlenecks in the process. Currently, the facility is working on expanding its product line and bringing in larger assembly line improvements. The project initially aims to create detailed process work instructions and identify opportunities to improve the overall efficiency and throughput of the side-dump final assembly line by 30% using an MES system.

The project's current state was measured by conducting an observed time study, which helped identify the bottlenecks in the assembly line. The time study results show, only 38% of the work done in the final assembly was value-added. Over 80% of the non-value-added times were wasted in - operator being idle, taking excess breaks, and waiting for parts.

In the future state design, identified problems were addressed using an MES system, carrying out assembly line balancing and various continuous improvement activities reduced the NVA time by 52%, which increased the production efficiency by 43%, and reduced the workforce by 25% - saving Demco potentially $315,460.00 a year.

Copyright Owner

Thangavel, Sanjay Raj

File Format


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