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Monday, October 8, 2012

Flexibility as processes mobility: The management of plant capabilities for quick response manufacturing


David M. Upton
Journal of Operations Management, No. 12, 1995

Summary
                  Improvement in flexibility is a key point of achieving achievements in competition in manufacturing, but at the same time the vagueness of the term determined at the same time its weakness. Flexibility can be distinguished among the internal capability of being flexible (capability) or the extern competitive need (mobility, Uton,1994). Another form of flexibility and be expressed by the ability of producing a wide range of products. Flexibility in academic is often relevant in the literature to four primary sources: economics, decision science, competitive strategy and manufacturing management. Different definitions have been taken, the author uses the following definition “flexibility as the ability to change with little penalty in time, effort, cost or time” and therefore he investigates the ability to change the product being manufactured, analysing in deep the context of mobility. The author visited 52 plants in North-America in the uncoated fine paper industry in 2 years, it’s an industry characterized by a growing need of flexible operations and often not able to achieve JIT, ending up with inventory and loosing money. The author interviews Vice-Presidents for Operations, COO, plant managers, paper machine superintendents and operators. The kind of industry is a typical low-cost product, where a plant has to hold a competitive price, the plants no able to remain competitive in cost have to be forced to stay busy since they have to balance pulp flow and continue to add value in the plant, so that flexibility appears to be an extreme point for a small and middle companies to survive. Changeover in this kind of production is also not easy to do complexity in operation, so that the goal is to perform change as swiftly as possible, a different degree of automation can be observed among companies and even operator may view it as a slowing and inflexible factor. Time to change grade on a machine appear then affected by: Plant Operations policies, Plant structure, Plant infrastructure and Managerial Emphasis. Plant operations policy is characterized by dimension of change (in colour, furnish, basis weight and calibre), magnitude (the time to effect change increases with the magnitude of the change, this is why often in the market production cycles are running on a two-week basis) and change frequency (plants which make frequent changes might be expected to make faster grade changes). The Plant structure is characterize on scale (increasing scale results in greater mechanical inertia of the components, and pressure that operator may impose themselves to change quickly may increase the cost of losing production on a big plant) and technology vintage (older low level technology may inhibit the ability of the plants operator to change). The plant infrastructure is characterized by computer integration (this may provide greater integration)and workforce experience (low levels increase time to change). Under the managerial point of view, flexibility appears to be a cultural background of the company and managerial approach.
Key Concepts
Flexibility
Key Results
It is clear that, in case of non-fully-automated processes, it is not possible to engineer a flexible approach, but relations between factors can be cleared and levels can be defined according on the market situation. The author, carrying different measurements to verify the factory describes above has shown different aspects for faster and older machines result in faster basis weight changes, while automation carried on general and repetitive task does not push the system to changes. Interesting is that each extra year of crew service is associated with four extra minutes taken to change grade, the crew experience causes inflexibility, but it is not related with any physical impediment due to age. Also interesting is that quick change overs are characterized with smaller change times. In the end it appears that a clear understanding of capability of flexibility is needed to fully access the tools of flexibility

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