The doctoral dissertations of the former Helsinki University of Technology (TKK) and Aalto University Schools of Technology (CHEM, ELEC, ENG, SCI) published in electronic format are available in the electronic publications archive of Aalto University - Aaltodoc.
Aalto

Modular Product Platform Design

Katja Hölttä-Otto

Dissertation for the degree of Doctor of Science in Technology to be presented with due permission of the Department of Mechanical Engineering for public examination and debate in Auditorium K at Helsinki University of Technology (Espoo, Finland) on the 12th of August, 2005, at 12 noon.

Overview in PDF format (ISBN 951-22-7767-0)   [894 KB]
Dissertation is also available in print (ISBN 951-22-7766-2)

Abstract

Modular product platforms, sets of common modules that are shared among a product family, can bring cost savings and enable introduction of multiple product variants quicker than without platforms. This thesis describes the current state of modular platform design and identifies gaps in the current state. The gaps were identified through application of three existing methods and by testing their usability and reliability on engineers and engineering students. Existing platform or modular design methods either are meant for (a) single products, (b) identify only module "cores" leaving the final module boundary definition to the designer, and (c) use only a limited set of evaluation criteria.

I introduce a clustering algorithm for common module identification that takes into account possible degrees of commonality. This new algorithm can be applied both at physical and functional domains and at any, and even mixed, levels of hierarchy. Furthermore, the algorithm is not limited to a single measure for commonality analysis.

To select the candidate modules for the algorithm, a key discriminator is how difficult the interfaces become. I developed an interface complexity metric based on minimizing redesign in case of a design change. The metric is based on multiple expert interviews during two case studies. The new approach was to look at the interface complexity as described by the material, energy, and information flows flowing through the interface.

Finally, I introduce a multi criteria platform scorecard for improved evaluation of modular platforms. It helps a company focus on their strategy and benchmark one's own platform to the competitors'.

These tools add to the modular platform development process by filling in the gaps identified. The tools are described in the context of the entire platform design process, and the validity of the methods and applicability to platform design is shown through industrial case studies and examples.

This thesis consists of an overview and of the following 6 publications:

  1. Hölttä, K., Suh, E. S., & de Weck, Olivier. Tradeoff between modularity and performance for engineered systems and products. In: Proceedings of International Conference on Engineering Design. Melbourne, Australia. August 15-18, 2005, to appear. © 2005 Design Society. By permission.
  2. Holtta, K. & Salonen, M. Comparing three different modularity methods. In: Proceedings of ASME 2003 Design Engineering Technical Conferences. Chicago, IL, USA. September 2-6, 2003. © 2003 American Society of Mechanical Engineers (ASME). By permission.
  3. Hölttä, K., Tang, V., & Seering, W. Modularizing product architectures using dendrograms. In: Proceedings of International Conference on Engineering Design. Stockholm, Sweden. August 19-21, 2003. A continuation submitted to RED Jan/Feb 04. © 2003 Design Society. By permission.
  4. Holtta, K. & Otto, K. Incorporating design complexity measures in architectural assessment. In: Proceedings of ASME 2003 Design Engineering Technical Conferences. Chicago, IL, USA. September 2-6, 2003. © 2003 American Society of Mechanical Engineers (ASME). By permission.
  5. Hölttä, K. & Otto, K. Incorporating design effort complexity measures in product architectural design and assessment. Design Studies, to appear. © 2005 Elsevier Science. By permission.
  6. Otto, K. & Hölttä, K. A multi-criteria framework for screening preliminary product platform concepts. In: Proceedings of ASME 2004 Design Engineering Technical Conferences. Salt Lake City, UT, USA. September 28 - October 2, 2004. Also to appear in Journal for Intelligent Manufacturing. © 2004 American Society of Mechanical Engineers (ASME). By permission.

Keywords: modularity, platform design, product architecture

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© 2005 Helsinki University of Technology

Last update 2011-05-26