Everyone Should Be a Waste Hunter
Documenting and recording the eight types of waste in any process is essential for any manufacturing operation. Here are a few tips on how to identify each type:
Continuous-improvement efforts begin with finding, then eliminating, the waste that exists in a process. In fact, waste elimination is the foundation of Lean manufacturing. I have previously discussed eight forms of process waste: defects, overproduction (completing work faster than the next process can handle), waiting (idle time), non-value-added processing, transportation (movement of materials), inventory, motion (movement of people or machines), and employee underutilization. Together, they form the handy acronym DOWNTIME. If these wastes can be eliminated, processes run smoother and output is more consistent.
In order to eliminate waste, we must first identify it. This cannot be accomplished by just a few managers, supervisors, or team leads. Training employees at all levels to be waste hunters is an important responsibility of today’s company leaders.
A simple, yet effective training tool is a Waste Walk, during which a group of employees follow a process from start to finish and record their findings. Here are a few tips for identifying each of the eight types of waste during a Waste Walk:
- Defects: Look for rejection/repair documents. Red tags might be attached to defective materials or products. There may even be a special quarantine area. Don’t rule out checking scrap bins, or even trash cans in the area.
- Overproduction: Look for work-in-process piled up between steps. Overproduced items can generally be found at bottleneck steps, due to more being produced in prior steps than can be consumed at the bottleneck. Check dates on work orders to see when parts were finished in prior steps of the process. Work orders that have been sitting for many days is further evidence of overproduction.
- Waiting: Don’t just think of this in terms of people (most employees will always find something to keep them busy; it just may be the wrong thing). Also look for work orders that are not being processed due to lack of needed parts, information, or personnel. Look for incomplete paperwork, or missing tools preventing a job from being completed.
- Non-Value-Added Processing: Look for steps in the process that are being repeated, such as counting, cleaning, and inspecting. Ensure all steps in the process are necessary. Also, ensure activities performed during one step of the process are not undone in the next.
- Transportation: Find anything moving within or between process steps. Although any process will involve some amount of product movement, look for excessive examples, such as long distances between process steps or frequent back-and-forth. Can complex workflows be simplified?
- Inventory: All processes require inventory of some type, but excessive inventory should be identified. Like overproduction, inventory waste is characterized by numerous materials or components waiting to be used. Look also at supplies, tools, and equipment to see if there are more than needed for current demand.
- Motion: Do employees mostly remain in their work areas, or do they tend to move around? Do they have what they need to do their assigned tasks, or are they frequently searching? Also consider the ergonomics of each process step. Are employees frequently reaching, bending, lifting, or changing from sitting to standing positions?
- Employee Underutilization: This waste can sometimes be more difficult to identify, but observing each step will provide clues on whether an employee’s skills, knowledge, and experience are being put to use. Look for evidence that employees are responsible for checking their own work, as opposed to giving it to others to check and approve. Do employees seem engaged in their work, or are their actions almost robotic? Are there opportunities for employees to be doing a little more during a process step, instead of handing the product off to someone else for further processing? Are there opportunities to develop skills and grow?
Written by: Wayne Chaneski, Executive Director, Center for Manufacturing Systems, New Jersey Institute of Technology, for Modern Machine Shop.