The very nature of most repair or service operations often results in a job shop approach to work execution. It is rare that 2 consecutive pieces of customer equipment were made by the same manufacturer, never mind the same model. With repairs and remanufacturing, the work scope usually differs, even on the same models of equipment, depending on the incoming condition of the piece. These and other factors provide excellent excuses for organizations to NOT implement Lean Manufacturing. In most cases, however, this is a big mistake, which prevents the service provider from capitalizing on many of the benefits of Lean, commonly thought to be applicable only to high volume, low mix operations.
Lean does not have to be implemented as an “all or nothing” program. Adopt what is helpful; discount what does not apply. It makes no sense, for example, to use a Kanban (pull through) parts ordering system that results in an automatic reorder of parts that may not be needed again for 6 years. Many of the principles of Lean, however, can drive reduced cycle time, better quality, reduced costs, and better cash flow, among other benefits.
A common repair scope in an electrical equipment repair facility is the rebuild of a medium voltage circuit breaker. The project value may be $15,000, and may require a 2 week stay in the shop, under normal circumstances. Typically, the breaker is placed at a work station, and assigned to one technician for the duration of the project. As parts are removed for cleaning, testing, repair, and painting, they travel around the shop, but ultimately are reunited on the work station as subservient processes are completed on them, usually by the same technician. Conventional wisdom cites benefits of single point accountability for the repair, maintaining productivity by not wasting time on communicating job nuances, tracking of parts, etc.
Were Lean to be implemented for this same repair, one might establish a series of closely located work stations, comprising a work cell. These might include:
- Incoming testing and inspection
- Disassembly
- Solvent parts cleaning
- Abrasive parts cleaning
- Component test and inspection
- Welding
- Coating and painting
- Reassembly
- Final test and inspection
Click “Before”, below, to see a typical “flow” in a job shop environment, prior to implementing Lean Manufacturing principles. Note that the arrows are inserted for only 1 of the 4 workers. See how far the equipment (and the worker), travels around the facility during the course of the project:
Before
Click “After”, below, for the flow of the same repair, post-Lean implementation. Note that the work stations within the cell have been grouped together. The volume in this situation is such that new projects are not begun each day. The work has been balanced, resulting in one operator handling more than one station. If throughput needs to increase, more operators can be used, to handle smaller numbers of stations. The black box outlines indicate the responsibility area for each technician.
After
Every circuit breaker will not need each of these activities, and more than likely, there will be different versions of the procedures based on the make and model of each breaker. But if and when the activity is performed, it will be performed by the designated employee, at the designated work station, in the designated work cell. Note: in the spirit of “all or nothing”, mentioned above, when it comes time for shop rearrangement to implement this approach, you work within reasonable budgets, and physical limitations. For example, it may not be worth $200,000 to move a tank which extends 10 feet into the building foundation, in order to save a few hours of cycle time on each project. You just do the best you can to maximize the available benefits. Just a few of the benefits that will be realized with this conversion:
Built-in Quality Assurance Checks
Rather than viewing each hand-off of the work between employees as an opportunity for miscommunication, it can be developed into an opportunity for a QA check. Doesn’t it make sense that Tom will be unlikely to accept the output of the previous step from Becky, if it does not meet quality requirements, knowing that he is accepting the responsibility for completing his own tasks in a quality manner. Each move between work stations in a cell provides another opportunity for such a QA step. Note: another Lean principle, that of Balancing the Line, may result in one employee working 2 or more of the work stations in a cell, if the cycle times of each station are to be balanced. See any good book on Lean Manufacturing regarding takt time for further explanation. Obviously, each employee working multiple station reduces the inter-project independent QA opportunities, but a balanced line offers additional benefits.
Visibility of Job Progress
No longer will it be necessary to interview the technician to guess how much longer the project will take, or how far ahead of, or more likely behind schedule it is. A breaker sitting in the welding station, when the schedule says it should be in reassembly, is visually evident to all who need to know. If your operation does not presently have a good work scheduling system, this may force an implementation of one.
Standard Work Implementation
In order to prevent monotony for the employees working in an “assembly line”, instead of as previously as an “artist” with single point responsibility for the project, it is good practice to rotate employees between work stations on a regular basis. To assure compliance with a quality system, and that each worker performs the same steps in the same manner, standard work approaches, documented in written procedures, become necessary if not already in place.
Improves Employee Assignment Flexibility
This approach provides fantastic opportunities to cross-train employees. If Sue is out of the shop on a road job, for example, one of her co-workers can now easily step into her place in the work cell, and the project no longer has to wait until she returns. Of course, not everyone has the talents to be trained as a welder, or a high voltage tester, but it does open the possibility to increase the skillsets of many of your employees. When this happens, a painter who previously had nothing to do when there was no painting, becomes more productive, and less cost goes against “shop cleanup” or other unproductive accounts.
This brief treatment of the topic does not even begin to cover the other changes necessary or the benefits to an implementation of Lean Manufacturing in a job shop. For further discussion, call StratXL to learn how applicable the approach might be for your operation, and check back here often for new articles on other opportunities to improve operations.