By offering dedicated flexibility in manufacturing systems, RMS represents an attractive trade-off between efficiency and flexibility, which is required when product variety and the rate of product introductions increase. Much literature has been published concerning different aspects of RMS; however, the majority of contributions report results from large manufacturing enterprises, which are expected to differ very much from SMEs, in terms of benefits and challenges of implementing RMS. Therefore, this issue was investigated by conducting a case study in a Danish SME that currently considered implementing reconfigurability, due to facing problems with high and resource-intensive changeover times.

The case studied in this paper is a Danish manufacturer of large industrial equipment that employs around 150 people. Products are manufactured using assemble- to- order strategy and consist primarily of large metal components which are cut, welded, and machined. Other components, such as electronics, are produced by sub-suppliers. The production is somewhat influenced by seasonal variations; however, due to the large degree of customization of the products, it is not possible to manufacture to stock in order to level the production.

The case company has long had an ambition to have a one-piece flow, in order to reduce stock and to reduce the lead time of manufacturing components, since manufacturing in large batches results in large stock. The annual production volume in pieces is relatively low (a few hundred, depending on product family), and a large number of components are used for each product. Hence, large batch sizes yield undesirably large stock. However, reducing batch sizes to a one-piece flow has proven impractical, due to the currently long changeover times. Many changeovers are influenced by the fact that welding large steel components requires large and heavy fixtures. Thus, changing from producing one component to another requires a change in the fixtures, as there is typically one fixture per component. In this particular case, this involves removing the previous fixture with a forklift, driving it to a warehouse, locating the new fixture, driving it to the welding station, and setting it up before the actual production can begin. These operations can take a significant amount of time compared to the actual welding time. This may seem as a classic example of balancing productivity and stock sizes, which can be addressed by lean methods, including single-minute exchange of die (SMED). However, traditional methods such as SMED cannot address the fact that the heavy fixtures are difficult and time consuming to handle, and thus a challenge remains in relation to this in the case company.

Due to the challenges outlined above, the case company has begun looking into applying the principles of RMS. The company expects that by applying RMS principles, it will be possible to introduce dedicated flexibility in welding cells, implying that a changeover from producing one component to another can be handled by reconfiguring a fixture rather than replacing it with a new fixture. The benefits of this are both in terms of more efficient handling of variants in production and improved ability to introduce new products.

Nevertheless, there are significant differences between realizing RMS in SMEs compared to large enterprises. One feature often described in literature for RMS is the use of parallel similar manufacturing lines, which produce components belonging to the same part family. These lines can be reconfigured from producing one variant to another variant within a certain period when market demand changes. However, the precondition for doing this is that the company produces a sufficient volume to sustain production of one single component on a manufacturing line over a longer period. This is not the situation in the case company, since the production volume is quite far from being sufficient for continuous production on even one line. This is expected by the authors to be the case in many other SMEs, producing low volume and high variety.

The RMS literature also describes principles for designing reconfigurable machines. This is highly relevant in the case company, especially reconfigurable fixtures. By reconfiguring fixtures rather than replacing fixtures every time a new component is to be produced, changeover time could be significantly reduced, as well as the time and resource usage for introducing new products or parts. As an additional advantage, this could potentially reduce the investment in fixtures, by distributing the fixture cost over multiple components. Furthermore, introduction of new products can be handled more efficiently and faster if the reconfigurable fixtures can be utilized in future part generations. It must be noted, however, that the frequency of reconfigurations must be expected to be much higher in SMEs with low volume compared to larger enterprises with higher volume. This implies that when designing the reconfigurable fixtures, increased focus must be on minimizing the reconfiguration time, as this would be a daily event in the case company, whereas large enterprises with higher volume may experience months or even years between reconfigurations, in which case a reconfiguration duration of several hours or even days may be acceptable. Although fixtures represent the most promising part of the production system to enable reconfigurability, this can highly likely be generalized to any other type of reconfigurable machine, e.g., machine tools, material handling, and inspection that are of similar relevance in other low-volume SMEs.

Since the case company has a limited production volume and high variety, the variety which is necessary to handle in one part of the reconfigurable manufacturing system is likely to be higher compared to a higher-volume large enterprise. This implies that reconfigurable machines, reconfigurable fixtures, etc. designed for SMEs are required to be reconfigurable across a much larger part variety, which must be taken into consideration.

Finally, there are large organizational differences between SMEs and large enterprises, which influence the feasibility of implementing RMS. Large manufacturing enterprises typically have production engineering departments addressing production system design, machine design, and tool design, whereas SMEs obviously have more limited capacity in production engineering and may rely on a handful of people when developing the production system or parts of it. Furthermore, SMEs may also rely on external consultants or machine developers to introduce new equipment in the manufacturing system. This may represent a challenge in terms of implementing reconfigurability in the production systems in the SME.

Changing a company's production system into a reconfigurable manufacturing system is in some way quite similar to introducing a product platform in product developmenta large investment is made up-front to reap large benefits on longer term. Similarly, developing an RMS will imply a larger short-term investment, but will ideally give large benefits on the longer term. However, this investment may seem to represent a too high a risk for a SME compared to large enterprises, which also may occupy too big a part of the smaller capacity in the production engineering department of the SME, which would also be a barrier toward implementing RMS.

Questions

17. (2 marks) Do you think that there might be a significant potential in implementing reconfigurable fixtures, as variety and new product introductions thus could be handled much more efficiently? If so, give reasons understanding the case. Limit your answer to the information given in this article.

18. (3 marks) Is it right in terms of this case that SMEs with low volume and high variety in general may benefit from implementing reconfigurability on workstation level, rather than on production line level? If so, give the reason(s) identified in the article.

19. (3 marks) In what aspects you believe that RMS addresses in SME and large enterprises are significantly different. Limit your answer to the information given in thsi article.

Reference:

Reconfigurable Manufacturing Systems in Small and Medium Enterprises, Thomas Ditlev Brunoe , Ann-Louise Andersen , and Kjeld Nielsen,ManagingComplexityProceedingsof the 8th World Conference on Mass Customization, Personalization, and Co-Creation (MCPC 2015), Montreal, Canada, October 20th-22th, 2015,Jocelyn Bellemare editor.; Serge Carrier editor.; Kjeld Nielsen editor.; Frank T Piller editor.; SpringerLink (Online service)