Guidelines to minimize variation whenestimating product line commonalitythrough product family dissection

Henri J. Thevenot and Timothy W. Simpson, Industrial and Manufacturing

Engineering, The Pennsylvania State University, 329 Leonhard Building,

University Park, PA 16802, USA

This paper discusses two experiments conducted to investigate the variation that

arises when estimating the Product Line Commonality Index (PCI) for a family

of products when using data gathered from product dissection. In the first

experiment, three main sources of variation were identified: (1) different levels

of dissection, (2) omitted components, and (3) different values for the factors

used to compute PCI. In the second experiment, guidelines for dissecting

subassemblies to the lowest level possible and predefined tables listing material,

manufacturing and assembly/fastening schemes were found to significantly

reduce variation, leading to more systematic and consistent methods of product

family analysis.

2006 Elsevier Ltd. All rights reserved.

Keywords: product design, design tools, user participation, product dissection

Todays highly competitive and global marketplace is redefining the way

many companies do business. They are faced with the challenge of pro-

viding as much variety as possible for the market with as little variety

as possible between the products. Instead of designing new products one at

a time, which results in poor commonality and standardization and dramati-

cally increases costs, many companies are now designing product families, al-

lowing the development of a sufficient variety of products to meet the

customers demands while keeping costs relatively low.

As more manufacturing companies seek to benchmark, redesign and consoli-

date their product lines, there is an increased need for systematic and consis-

tent approaches to product family dissection and analysis. While methods

have been proposed for product family redesign and benchmarking (Thevenot

et al., 2005; Thevenot and Simpson, 2006), a major problem is the way in

which information is collected. When product design information is not read-

ily available, product dissection needs to be performed on the products in the

family being redesigned to collect appropriate information. The problem with

product dissection is that it is a heavily human-based activity, and variation in

the information collected can occur, such as differences in the level of

Corresponding author:

T. W. Simpson

tws8@psu.edu

www.elsevier.com/locate/destud

0142-694X $ - see front matter Design Studies 28 (2007) 175e194

doi:10.1016/j.destud.2006.07.004 175 2006 Elsevier Ltd. All rights reserved. Printed in Great Britain