Diagnosing Operational Waste and Barriers to Material-Value Retention in Project-Based Welding: An Integrated VSM-PAM and Thematic Analysis Approach

In the world of manufacturing, there is a constant tension between the flow of work and the cost of waiting. When a factory makes thousands of identical items on a conveyor belt, the goal is simple: keep the parts moving so that every second counts. But when a factory builds unique, complex projects—like the custom frames for trains or heavy machinery—the rhythm changes. Here, work arrives in bursts, different pieces arrive at different times, and the quality of the final product depends on a chain of checks that can easily get tangled. In these environments, valuable materials often sit idle, or worse, get damaged and discarded, because the system is not designed to handle the messiness of custom work. To understand where value is lost, experts look for two things: the time that adds worth to the product, and the time that simply wastes it. They also look for the hidden barriers that stop materials from being used fully, such as poor planning or a lack of coordination between workers.

A recent study focused on a specific type of project-based welding used to build rolling stock, the heavy metal frames that support train cars. The researchers wanted to see exactly how time and material were being used in a real-world setting where the work is never quite the same twice. They did not rely on guesswork or computer models alone. Instead, they went directly to the factory floor to watch the work happen. They mapped out the entire journey of a single project, from the moment the raw metal arrived to the moment the finished weld was inspected. They tracked every second the metal was being worked on and every second it was just sitting there. To get the full picture, they also spoke with the people doing the work, asking them about the difficulties they faced and the reasons why things sometimes stalled.

The team combined two different ways of looking at the process. One method drew a detailed map of the timeline, showing exactly how long the project took and where the delays happened. The other method looked at the specific actions the workers took, sorting them into three categories: work that actually shaped the metal, work that was necessary but did not change the metal, and work that was pure waiting. They also looked for eight common types of waste that plague manufacturing, such as making too many parts too early, moving materials around unnecessarily, or fixing mistakes that should not have happened in the first place. To understand the human side of the problem, they analyzed interviews with four key workers, looking for patterns in what they said about their daily challenges.

The results revealed a system that was far less efficient than it appeared. The total time from start to finish for the project was nearly 170 hours. Of that massive amount of time, only about 90 hours were spent actually welding and shaping the metal. The remaining 79 hours were spent waiting. When the researchers broke down the work further, they found that just over half of the time was spent on tasks that added value. A tiny fraction was spent on necessary tasks that did not add value, like moving a part to a better spot for inspection. But nearly half of the entire timeline was lost to waiting. Every single type of operational waste was present in the process. The metal was sitting around, parts were being moved back and forth, and there were instances of over-welding, where more material was used than needed.

The study identified that these delays and wastes were not random accidents. They were the result of a web of connected issues. The most significant problems stemmed from how well the workers followed the rules for welding sequences and standards. When the inspection process was unclear or when the right tools and materials were not ready when needed, the entire line stopped. Communication gaps between different teams meant that information did not flow smoothly, and sometimes the workers lacked the specific training or discipline required to keep the process moving without errors. The researchers also found evidence that the factory was not fully capturing the value of its materials. While some scrap metal was being separated for recycling, there were missed opportunities to reuse leftover pieces or to use production resources more efficiently.

The study suggests that the problems of wasted time and wasted material are deeply linked. The waiting, the piles of unfinished work, the extra welding, and the need to fix defects all come from the same root causes: a mix of process flaws, quality control issues, unprepared resources, and human factors. By looking at the factory through this combined lens, the researchers were able to show that fixing the operational waste is the same as fixing the barriers to keeping material value. The findings do not offer a magic solution or a quick fix, but they provide a clear, detailed diagnosis of where the system is breaking down. They show that in project-based welding, the path to saving money and materials lies in understanding the complex relationship between the people, the rules, and the flow of work itself.