Product life management system in digital manufacturing environement.

Mocan, Marian Liviu ; Belgiu, George ; Izvercianu, Monica 等

1. INTRODUCTION

The new generations of the Product Life Management (PLM) systems are now solving various difficulties from the previous technology, bordering on Web 2.0 principles for answering company needs for manufacturing process optimization purposes.

Certainly, all existing PLM systems are resolving the storage obstacles, working out on decisions (by means of fuzzy logic, linguistic summaries, semantic webs, decision trees, and genetic algorithms). We are going to realize a new PLM system (called Custom PLM). For this system we are concerned with the PLM engine (for CAD conversion, workflows, and data processing), decision and classification module, search engine, interface module, and interchange module. Also, for a PLM system important issues are: Product Structure visualization, migration abilities, process execution and load balancing. We consider a large company, producing electric motors for general use.

[FIGURE 1 OMITTED]

The company has 20 years experience in CAD/CAE systems, and 15 years experience in CAM technology. An example of 3D CAD model for the general assembly of an electric motor is presented in figure 1. The assembly contains approximately 345 objects (parts or files). We have to consider that the company's business is represented by the production of special electric motors, three-phase and single-phase motors, brake electric motors, electric motors for washing machines and different types of special electric motors. Each of them has more than 200 parts, and in each category we have from 6 to 20 types (depending on power, dimensions, number of rotations per minute etc.).

[N.sub.OB] = [N.sub.EM] + [N.sub.J] + [N.sub.CAM] + [N.sub.CAE] + [N.sub.Q] + [N.sub.IA] (1)

Generally, equation (1) presents the number of parts managed by the PLM system database ([N.sub.OB]--the number of objects), depending on [N.sub.J]--the necessary number of mechanical jigs, fixtures, molds and other devices, [N.sub.CAM]--the number of CAM objects, [N.sub.CAE]--the number of CAE simulation elements, [N.sub.Q]--the number of quality assurance files, and [N.sub.IA]--the number of additional information assets.

In our case, [N.sub.OB] [approximately equal to] 3.500.000 objects, and the number is growing with the rate 55.000/monthly. Most of the objects are Pro/ENGINEER[R], SolidWorks[R], CATIA[R] Tecnomatix[R] Delcam[R], and Microsoft Office[R] documents. The equation (1) can be rewritten:

[N.sub.OB] = [n.sub.K1 x K2] + [K.sub.3] x f(A, B, C) (2)

where: n--the number of eclectic motors types, K1 and K2--coefficients depending of the Product Data Management system, [K.sub.3]--a constant depending on PLM system, A--the number of Collaboration and Project Management objects, B the number of CAD and Software Integration objects, C--the number of Enterprise Integration objects.

As we mentioned before, the company has a fragmented IT architecture (hardware and software) and, at this point, the correct decision for selection of an appropriate PLM system is a crucial step.

2. CRITICAL OVERVIEW AND THE RESEARCH

2.1 Critical overview

Today, many PLM systems are implemented all over the world. Major commercial players, such as Windchill[R], Teamcenter[R], Enovia[R] and others, are very well known for the role in the process of managing the entire lifecycle of a product from its conception, through design and manufacture, to service and disposal, as is presented in (*** 2009 a; b; c; and d). PLM integrates people, data, processes and business systems and provides a product information backbone for an extended enterprise. From copyright reasons, in our work we do not refer to a specific PLM system. We will instead a Commercial PLM system no.1, a Commercial PLM system no.2, and so on. Numerous authors, like (Lee, 1999) consider the Product Lifecycle Management system is more close of managing features of a product through its growth and life, mainly from a business and engineering point of view; whereas product life cycle management (PLCM) is to do with the life of a product in the market with respect to business and commercial costs, sales and measures (Ni et al., 2008; Batenburg et al., 2005).

Several of the PLM Commercial systems have emerged out of the CAD and PDM market. The subject of our work was to develop an independent PLM system, for a medium company, customized according their needs and their market. A new PLM system must be compliant with Web 2.0, a second generation of web development and web design. Using this new technology, the PLM system is facilitating communication, information sharing, interoperability, user-centered design and collaboration inside of the enterprise based on the WWW space. The new technology has led to the development and evolution of the traditional CAD/CAM/CAE systems, emerging in a web-based communities, hosted services, and web applications in the digital factory.

2.2 Research course, technical solution

Our aim was to develop a Custom PLM system (i.e. an electric motors company), with the system software keeping track of all work and all changes in a set of files, and allowing several engineers and technicians (potentially widely separated in space and / or time) to work /collaborate.

The custom PLM system we designed must fulfill a number of ordinary functions, featured in figure number 2.

[FIGURE 2 OMITTED]

For the operating system we adopted the Linux distribution openSUSE, supported on an x86-64 platform. For the relational database management system we adopted MySQL version 5.1. This cross-platform software application runs as a server providing multi-user access to our Custom PLM module.

3. THE NEW RESULTS

In our university laboratory we compared a Commercial PLM system number one (PLM#1), and a Commercial PLM system number two (PLM#2), against our Custom PLM designed for the electric motors company. The measured parameters were:

* P1--NOB manipulated;

* P2--price of server installation and 50 clients (workstations);

* P3--PDM capabilities;

* P4--price of operation, training and maintenance capabilities;

* P5--collaboration and Project Management capabilities;

* P6--CAD and software integration capabilities;

* P7--enterprise integration capabilities;

[FIGURE 3 OMITTED]

The figure number 3 shows only a partial complexity of the observable facts and could be one-sided, but was confirmed by the experiments.

4. CONCLUSION

All PLM systems analyzed in this work do not satisfy the entire needs for P5, P6 and P7. That is mean, if a company have a variety of CAD/CAM/CAE software tools, heterogenic ERP and hardware, will be in a difficult position to select the suitable PLM system. For a middle range organizations, it will be a good alternative to develop the own (custom) PLM system. The efforts will be compensate by the greater productivity, high level of speed, functionality, and security.

For our custom PLM collaboration software, further research will be oriented to optimise the web interface, in order to enables companies to streamline product development processes, a high-performing technology platform, regardless of source for software tools and hardware systems.

5. REFERENCES

Batenburg, R.; Helms, R. & Versendaal, J. (2005). The maturity of Product Lifecycle Management in Dutch Organizations. A strategic alignment perspective. Available from: http://www.cs.uu.nl/research/techreps/repo/CS-2005/2005009.pdf. Accessed: 2009-04-22

Lee, K. (1999). Principles of CAD/CAM/CAE Systems, Addison-Wesley, pp. 291-319, ISBN 0-201-38036-6, Reading Massachusetts

Ni, Q.; Lu, W.F.; Fang, W.; & Yarlagadda, P., K. (2008). An extensible product structure model for product lifecycle management in the make-to-order environment. Concurrent Engineering: Research and Applications (CERA), 16(4). pp. 243-251, ISSN:1531-2003, http://eprints.qut.edu.au/ 14638, Accessed: 2009-04-16

*** (2009 a) http://www.ptc.com/products/windchill/--Reduce Risk. Drive Value; Production-proven content and process management software, Accesed on:2009-06-0

*** (2009 b) http://www.plm.automation.siemens.com/en_us/ products/tecnomatix--Transforming the process of innovation, Accesed on:2009-05-2

*** (2009 c) http://www.plm.automation.siemens.com/en_us/ products/teamcenter/index.shtml--Teamcenter, Accesed on:2009-05-25

*** (2009 d) http://www.3ds.com/products/ enovia-ENOVIA Collaborative Product Lifecycle Management, Accesed on:2009-04-20