Many companies develop a market strategy built around a family of products. These companies regularly add new product variations to the family in order to meet changing market needs or to attract a broader customer base. Although the core functionality remains essentially unchanged across the products within a family, new functions, feature combinations and technologies are incorporated into each new product. If allowed to grow unchecked, these component variations, commonly referred to as “complexity”, can result in a loss of productivity or quality. The challenge lies in an effective management of product variations in the design studio and on the manufacturing floor. The key is to minimize non-value added variations across models within a product family without limiting customer choices. In this paper we discuss the factors that contribute to product complexity in general, and present an objective measure, called the Product Line Commonality Index, to capture the level of component commonality in a product family. Through our Walkman case study, we present a simple yet powerful method of benchmarking product families1. This method gauges the family’s ability to share parts effectively (modularity) and to reduce the total number of parts (multi-functionality). [S1050-0472(00)02704-5]

1.
MacDuffie, J. P., Sethuraman, K., and Fisher, M. L., 1996, “Product Variety and Manufacturing Performance: Evidence from the International Automotive Assembly Plant Study,” Manage. Sci.
2.
Clark, K., and Fujimoto, T., 1991, Product Development Performance: Strategy, Organization and Management in the World Auto Industry, Harvard Business School Press, Boston.
3.
Womack, J. P., Jones D., and Roos, D., 1990, “The Machine that Changed the World,” Rawson Associates, New York.
4.
Sanderzon, S. W., and Uzumeri, V., 1997, “Managing Product Families,” Irwin.
5.
Kekre
,
S.
, and
Srinivasan
,
K.
,
1990
, “
Broader product Line: A Necessity to Achieve Success?
,”
Manage. Sci.
,
36
, No.
10
, pp.
1216
1231
.
6.
Whitney
,
D. E.
,
1993
, “
Nippendenso Co. Ltd: A Case study of Strategic Product Design
,”
Res. Eng. Des.
,
5
, pp.
1
20
.
7.
Ulrich
,
K.
,
1995
, “
The Role of Product Architecture in the Manufacturing Firm
,”
Res. Policy
,
24
, pp.
419
440
.
8.
Sethuraman, K., 1994, “The Impact of Product Variety on Manufacturing Performance: An Empirical Investigation of the World Automobile Industry,” Ph.D. thesis, Wharton School, University of Pennsylvania.
9.
Pine, J., 1992, Mass Customization: The New Frontier in Business Competition, Harvard Business School Press.
10.
Ulrich, K., and Tung, K., 1991, “Fundamental of Product Modularity,” ASME Winter Annual Meeting Symposium on Issues in Design/Manufacturing Integration, Atlanta.
11.
Brooke, L., Nov., 1994, “Coping with Complexity,” Automotive Industries.
12.
Baker
,
K. R.
,
Magazine
,
M. J.
, and
Nuttle
,
H. L. W.
,
1986
, “
The Effect of Commonality on Safety Stock in a Simple Inventory Model
,”
Manage. Sci.
,
31
, pp.
982
988
.
13.
Gerchak
,
Y.
,
Magazine
,
M. J.
, and
Gamble
,
A. B.
,
1988
, “
Component Commonality with Service Level Requirements
,”
Manage. Sci.
,
34
, pp.
753
760
.
14.
Dertouzos, L. M., Lester, R., and Solow, R., 1989, Made in America: Regaining the Productive Edge, The MIT Press, Cambridge.
15.
Farrell
,
J.
, and
Saloner
,
G.
,
1985
, “
Standardization, Compatibility, and Innovation
,”
Rand J. Econ.
,
16
, No.
1
, pp.
70
83
.
16.
Farrell
,
J.
, and
Saloner
,
G.
,
1986
, “
Installed Base and Compatibility: In, Product Preannouncements, and predation
,”
Am. Econ. Rev.
,
76
, No.
5
, pp.
940
955
.
17.
Fonte, W. G., 1994, “A deproliferation Methodology for the Automotive Industry,” Masters of Science Thesis, Massachusetts Institute of Technology, Leaders for Manufacturing Program.
18.
Gupta, S., and Krishnan, V. K., 1997, “A Product Family-Based Assembly Sequence Design Methodology for the Economic Attainment of Product Variety,” Working Paper University of Texas, Austin.
19.
Lee, H., and Billington, C., September, 1992, “Designing Products and Processes for Postponement,” presented at the conference on Design Management, Anderson Graduate School of Management, UCLA.
20.
Vakharia, Asoo, Parmenter, David, and Sanchez, Susan, 1996, “The Operating Impact of Parts Commonality,” Journal of Operations Management, 14, November.
21.
Iyengar
,
G.
,
Lee
,
C-L
, and
Kota
,
S.
,
1994
, “
Towards an Objective Evaluation of Alternate Designs
,”
ASME J. Mech. Des.
,
116
, pp.
487
492
.
22.
Kota, S., and Chiou, S. J., 1992, “Conceptual Design of Mechanisms Based on Computational Synthesis and Simulation of Kinematic Building Blocks,” J. Res. Eng. Des. No. 4, pp. 75–87.
23.
Kota
,
S.
, and
Lee
,
C. L.
,
1993
, “
A General Framework for Configuration Design Part 1: Methodology, Part 2: Application to Hydraulic Systems Synthesis
,”
J. Eng. Des.
,
4
, No.
4
, pp.
277
303
.
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