IEN: How do you see the role of automation in lean assembly?
Tompkins: Assembly automation has a long history of application in both lean and non-lean environments. Automation can be an effective approach to reducing costs, but several factors must be considered. The first is the potential for automation to run at 100% output. If the automation is a source of process downtime it becomes a stumbling block to lean implementation. Second, a careful evaluation must be done to ensure that the value of the direct labor saved is not offset by increases in indirect costs for technical support and management. Time after time, significant savings have been achieved in direct labor costs only to be replaced by other indirect costs. Automation, used wisely, is encouraged in a lean environment. Automation done without lean concepts in mind will impede lean implementation.
IEN: What are the major challenges facing the implementation of the lean enterprise and how can they be addressed?
Tompkins: Only recently has the creation of a truly lean enterprise been viewed as a feasible objective for any value stream to undertake. Companies have begun to understand the tremendous improvement potential in integrating the supply chain. They are recognizing waste to be removed from all aspects of the supply chain in order to get the most benefit from supply chain improvements.
The challenges facing the lean enterprise are all the same challenges faced by lean implementation at the plant or division level, but magnified many times as the size of the structure and complexity of the relationships grows. Problems faced by organizations who want to create a lean enterprise include lack of technical and practical knowledge, lack of discipline to maintain improvements, lack of support from accounting and finance departments, resistance to change from all levels of the organization and across organizations, and inadequate focus and leadership from management. The fact that US companies have been slow to adopt lean practices points to the uphill struggle the leaders of the lean enterprise movement have to educate and grow lean application across the supply chain.
Addressing lean enterprise thinking can only be done by a systematic education and learning process by proponents of lean. As emphasis on supply chain level improvements begin to take hold, the concepts of lean as the improvement framework will also take hold. Something we have to remember is that Womack, Jones and Roos first wrote about the lean enterprise in their 1990 book The Machine That Changed the World. The transformation to the lean enterprise will take time to accomplish.
IEN: What are the pros and cons of cellular assembly?
Tompkins: The goals of any assembly operation are to produce quality products, make the most efficient use of labor, minimize inventories needed to sustain production, have the flexibility to change what is being produced and the output level, produce the required number of products in a given period of time, and ensure the safety of the workers. Well-designed cellular layouts meet these goals by:
- Providing processes for workers to ensure quality at the source
- Standardizing processes and documentation of quality expectations
- Being flexible enough to allow workers to perform multiple tasks through cross-training and people movement
- Minimizing WIP stored at the line
- Operating the line with a pacemaker
- Optimizing assembly workers'' efforts on assembly and proving standardized material presentation.
Cellular layouts are not always the best answer. Sometimes the product being produced and the volume or output required makes a cellular layout impractical or unnecessary. Assembly of very large products such as airplanes may not be good candidates for a cellular approach, but many of the concepts of cellular layout design should be used in subassemblies and material delivery.