We’re now at the point where everyone is on board with the idea of change. Management and staff have indicated a willingness to take steps to improve. So how do we proceed?
What processes learned from Lean Manufacturing can we use to make progress?
As discussed last month in the 5th article in our series, “So You and Your Company are Ready to Accomplish New Goals and Take the First Steps to Improve,” the DMAIC process is a very effective tool for pinpointing waste in both processes and fabrication. DMAIC stands for Define, Measure, Analyze, Improve, and Control. To develop this line of thinking, this article will use a case study based on a typical setup found in many truss manufacturing plants. After setting the parameters, I will outline the DMAIC Lean method and demonstrate how this process can be used to improve efficiencies.
Case Study:
- Equipment Parameters: A company possesses a linear saw and a 100 L’ roof truss gantry with 2 setup and fabrication stations, supported by an automated puck system and carts to transfer cut parts from the saw 50’ to the table.
- Project Parameters: Single Family, L shape house, front to back 36’-0 x side to side 66’-0 with a 22’-0 x 22’-0 garage set on the right side. House has a mix of commons, gable ends vaults, and scissors trusses with a valley integrating perpendicular garage trusses. The longest run is 11 trusses, with many shorter runs of 1 to 5 trusses. Total number of setups is 16.
- Baseline Productivity: For this type of residential project: 85+/- Bd’/ mhr and 18+% labor.
The DMAIC method starts with …
- Define—identify the scope of the problem and new goals.
To obtain greater profits, the labor rate for this type of project needs to drop and Bd’ productivity needs to increase to 100 Bd’ per man hour.
- Measure—calculate current data and time to establish a baseline for each defined problem.
Baseline measurement, stated above.
- Analyze—determine how this process and potential improvement will impact the organization and affect revenue growth and profits.
Improvement of labor percentage and Bd’output could reduce the expense of overtime, allowing the company to sell and process additional work, and diluting overhead expense and increasing profits.
- Improve—develop a strategic plan to increase efficiency.
Where is the waste in your process??? Lean is all about identifying and reducing waste.
Excessive transportation? Moving carts of cut parts 50’ from the linear saw to the assembly table.
Waste of motion? Having cut parts on a cart for both the left and right side of truss, requiring extra steps for the fabricator to obtain and set cut parts to the jig and assemble truss.
Over production? To reduce saw process time, most plants cut and batch as many trusses for the run as possible. Yet trusses are built one at a time. To minimize excessive transportation, carts are overloaded with parts that require time to find and sort.
Extra inventory? Jig change-overs take more time to execute than building the truss. What takes the most time to setup a new truss? Automated pucks setup the perimeter, but waiting for parts to be retrieved from storage or the saw, finding, pulling and distributing connector plates is a cycle time killer.
To make sure that you are on the path to real change and productivity gains… you need to continue to measure and quantify each improvement step!
- Control—implement a detailed plan to maintain improvements.
The last step in the DMAIC process is the most important. Improvements that are not maintained have diminishing returns. Once you have obtained improvement and new goals, you need to sustain them. How do you do that? A control plan that holds everyone accountable and keeps improvements thriving is the key.
Next Month:
Additional ways the DMAIC process can drive improvement and how you can create a culture of continuous improvement