Helping a Specialty Materials Producer Embrace PDCA Culture
DPA recently worked with a manufacturer of wire, cables and connectivity products to reduce scrap at one of their factories. The kaizen team worked with DPA to reduce scrap on a wire product line that represented nearly a third of the company’s sales in just 18% of its production volume.
Understanding the Current Situation
The team reviewed the scrap components by going through the scrap log. Reviewing the scrap log showed that the bulk of the scrap was occurring in stranding. When the team reviewed the summarized data with the CEO, he questioned the validity of the data. He then asked the team to go empty the scrap bins from the scrap processing area to see where the bulk of the scrap was being generated. To his surprise, this manually acquired data also supported the initial data findings that the largest amount of scrap was being generated in the stranding process.
Creating and Running Trials
Focusing on inputs for the wire stranding process, the team used basic physics in order to calculate the expected ideal combination of input weights for the line’s six-wire and seven-wire spools in order to yield zero scrap left on the spools after the stranding process is completed. During the first trial run, the team also made live observations of the thread tensions and wire uptake issues that occurred during the production run. (see Figure 1, Calculating the optimal spool weight inputs that will yield zero scrap).
Calculating the wire amounts using basic physics did not bring them to a net scrap of zero. The team realized that a full Taguchi analysis to understand the impact of all input variables may be necessary. As an interim solution, the team chose to use an empirical version of analysis by performing multiple iterations of spool weight combinations while only changing one variable at a time in order to zero in on the right amount of wire for each spool.
Analyzing Outcomes; Planning for the Future
The team reviewed the combination of inputs and results after each test iteration in order to further refine the input spool weights based on observations from the trials. The review helped them create new data set targets that would both maintain yield and continue to reduce scrap. The outcomes of these trials also helped them begin to establish standard work, formalize inputs and collect data for all other product lines in the plant.
Results to Build Upon
At the conclusion of this initial event, the team was able to reduce one wire line’s scrap rate from 8.2% to 4.1%, a 20% reduction of scrap, or 27,400 pounds. Applying this same methodology to the other lines can, over time, help the company reduce scrap by up to 50%.
The Kaizen event itself had very significant and long-lasting results. The introduction of applying the scientific method in an effective teaming environment resulted in a huge cultural change for the company. Employees are now regularly using physics, scientific method, and data in ongoing trials that are reviewed in monthly PDCA meetings.
Encouraged by the team’s initial success and their collaborative effort, the company’s CEO authorized a second kaizen event to further reduce scrap across all the facility’s machines.
Read here to learn what happened during the company’s second scrap reduction event.