Wonder

Research Outline

Prepared for Mike | Delivered August 21, 2019

Efficient Leather Product Sewing

Goals

To find the most productive ways to sew/manufacture leather products in order to guide process implementation.

Early Findings

While we couldn't find data on a particular way or a process proven to be the most productive way to sew/manufacture leather products during our preliminary research, we found a couple of studies that have analyzed the sewing process in a bid to find the best way to improve production efficiencies. 
A study analyzed "the best combination of SPC (stitches per cm) and class of stitch construction (SC) that presented the best seam performance or seam quality in terms of seam strength, seam efficiency and thickness strain" during leather product production.
The study found that "seam strength amplified with the increase of SPC up to certain level. The seam with 301 SC at 3 SPC provided the best seam performance whereas seam with combination (401 and 304) at 3 SPC shown significant seam strength as well."
We found a peer-reviewed paper published in December 2018 that investigated how production (Sewing) efficiency of Lean Manufacturing based system can be improved. Although the paper is primarily focused on Apparel sewing, its lessons can be applied to leather as the sole focus of the research is on improving the sewing department efficiency. 
The researchers studied a typical sewing department and found that the most common causes of inefficiency during sewing include lack of training, lack of understanding of machine mechanism, absent workers, and inefficient use of high skilled labor (Jumpers). 
Other factors include lack of preparation during style changes which lead to more stoppages of modules. In addition to that, Lack of planning in the cutting department leads to stoppages of modules due to the lack of supply of raw materials for each section.