Reorganisation of production system on SME enterprises.

Karaulova, Tatyana ; Shevtshenko, Eduard ; Polyanchikov, Igor 等

1. INTRODUCTION

In order to survive under the conditions of the global crisis the enterprises are forming the collaborative networks. The network participant enterprises must have the common base. In order to improve (quality, cost, and time) production activities, it is necessary to know the source of an enterprise's problem(s). However, in order to find the enterprise's problem, it is important to define and understand the source and core of the problem. After the problems list is received the enterprise reorganisation process could be started.

Enterprise performance management (EPM) is a set of management and analytic processes, supported by technology, that enable businesses to define strategic goals and then measure and manage performance against those goals. EPM processes include financial and operational planning, business modelling, analysis, and monitoring of key performance indicators (Salvendy, 2001).

There are three main factors that production managers fear most: (1) poor quality, (2) an increase in production cost, and (3) an increase in lead time. These three factors are signs of poor production management. Production improvements should be based on improvements to processes and operations. In a production area, problems can appear in any of the basic elements that constitute the area (Santos et al., 2006).

Flexible Manufacturing Systems (FMS) have been conceived and implemented in real situations. These systems generally consist of a series of machines and storage systems linked by a material handling system, all controlled by a network of computers. Improvements ensure that the enterprise will be reliable partner for the collaborative network after reorganisation is completed.

2. MODEL OF SYSTEM REORGANISATION

Business process restructuring is the analysis and design of workflows and processes within organizations. This process should be started before enterprise can join the collaborative network. Manufacturing enterprise improvements should be based on improvements to processes and operations. In a production area, problems can appear in the any of the basic elements: machines processes, products, processing routes, volume ranges, expansion opportunities, operational logics, production strategies.

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The following methods will be used in the research: Functions modelling and simulation; Production flow analysis (PFA); Neural networks; Group Technology; Cell manufacturing; Lean manufacturing methods; Facilities Planning methods. In figure 1 are introduced the conceptual model of production system reorganisation is introduced.

The process can be divided into three main levels:

* Analysis of the existing or planed production and group technology elaboration.

* Production process analysis.

* Production process and product warehousing organisation.

2.1 Products analysis

Manufacturing system reorganisation starts with existing productions analysis, its grouping together to take an advantage of their similarities. Group Technology (GT) is applied to identify part families and their associated machine groups so that each part family is processed within a machine group. The process of identification of a part family and its associated machine groups is called cell formation. The advantage of a cell formation is that it reduces material handling time, work-in-process, throughput time, setup time, delivery time, and space. Furthermore, it provides the operational benefits of flow line production, simplification of quality control and increased job satisfaction (Venkumar & Noorul Haq, 2006).

GT is a useful way for increasing the productivity of the high quality products manufacturing and improving the flexibility of manufacturing systems. It can be use neural networks to infer a technology process observation. Neural networks are useful in approach where the complexity of processes makes the design of such a process by hand impractical. This approach uses the neural network paradigm for cell formation (Fig.2). Application also includes knowledge discovery in databases (data mining).

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2.2 Production process analysis

The system analysis starts from the modelling of production process for every group of products. Models allow to learn about the system and test various system designs (Askin & Goldberg, 2002). On the base of simulation these models by using several scenarios may be obtained needed results for equipment and workers loading, productivity of the process. Also, model of a process gives sequence of equipment using (Fig 3). All this data will be used for carrying out production flow analysis and manufacturing cells elaboration.

Modelling of production systems will allow to test out in advance the impact of planning and control decisions and therefore avoid making errant decisions and minimize the disruption to the real process.

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2.3 Production Flow Analysis (PFA)

Further a PFA analysis method will be applied and it will be aimed on optimization of material flows in scope of logistic goals The main method of the PFA is a quantitative analysis of all the material flows taking place in the factory, and using this information and the alternative routings for the manufacturing groups forming that are able to finish a set part with the resources dedicated to it. Depending on the scale of the project this logic is applied on company, factory, group, line and tooling level respectively. The work is broken down into the following steps for every case:

* to identify and classify all production resources, machines and equipment;

* to track the all product and part routes that the company, factory or group produces;

* to analyse the manufacturing network main flows formed by the majority of parts;

* to study the alternative routings and grouping of the machines for the fitting of parts into a simplified material flow system.

PFA provides well-established, efficient and analytical engineering method for planning the changes from "process organisation" up to "product organisation". The traditional production layouts are transformed into production groups, where each group is the particular set of parts equipped with a particular set of machines and equipment enabling them to complete the assigned parts. Fig.4. illustrates the conventional process layout and its corresponding product based layout after PFA has been applied.

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2.4 Cells organisation

The cellular manufacturing is a production method adopted for industrial control component manufacturing from early time because this system is an effective manufacturing method for wide-variety-small-volume production. (Kamoda et.al., 2006) However, the quality of products often depends on employees in this system. The most important for keeping of high quality of products are small manufacturing volume and the control of quality dispersion in manufacturing process Cells organisation leads to the following activities:

* To assign part families to groups of machine types,

* Define the lot sizes of the parts produced,

* To determine the number of machines needed of each machine type,

* To assign parts to individual machines,

* To group individual machines into manufacturing cells.

Machining and assembly operations are value-adding activities while transportation and storage are non-value-adding activities. Reduction in non-value-adding times will lead to shorter cycle time and consequently work-in-process inventories will be lower. Reduction in non-value-adding activities leads to lean manufacturing (Tompkins et al., 2003).

Many companies are focused on Lean manufacturing for world class productivity achievement and profitability increase under the global competition conditions. The lean manufacturing concept can be summarized as follow:

* Eliminate or minimize non-value adding activities.

* Produce only what is demanded.

* Minimize the use of time and space resources.

* Manufacture in the shortest cycle time possible.

Implementation of the Lean model depends from the company's maturity level before starting the program of changes.

3. CONCLUSIONS

Enterprise reorganisation is the first step on the way to the reliable collaboration. This can also lead to the improvement of economic parameters of performance. An integrated modelling method based on system modelling has the capability to analyse and design manufacturing systems.

4. ACKNOWLEDGEMENTS

Hereby we would like to thank the Estonian Ministry of Education and Research for targeted financing scheme SF0140113Bs08 that enabled us to carry out this work.

5. REFERENCES

Askin, R. & Goldberg, J. (2002)--Design and Analysis of Lean Production Systems, ISBN: 0-471-11593-2 John Wiley & Sons Inc.

Kamoda, H.; Hotta, T.; Nakatsuka N. & Sugawa, S. (2006) A Novel Production System for Wide-Variety-Small-Volume Production, ISBN 1-4244-0148-8, IEEE

Santos, J., Richard A. Wysk, Jose M. Torres (2006)- Improving Production with Lean Thinking, ISBN: 978-0-471-75486-2, John Wiley & Sons Incorporated

Salvendy G., (2001)--Handbook of Industrial Engineering: Technology and Operation Management, A Wiley-Interscience. ISBN 0-471-33057-4

Tompkins, J.; White, J.; Bozer, Y. & Tanchoco, J. (2003) Facilities Planning, John Wiley & Song, Inc. ISBN 0-47141389-5

Venkumar, P. & Noorul Haq, A. (2006) Fractional cell formation in group technology using modified ART1 neural networks, Int J Adv Manuf Technol DOI 10.1007/s00170004-2421-z