Cox, I D; Morris, J P; Rogerson, J H and Jared, G E (1999) A quantitative study of post contract award design changes in construction. Construction Management and Economics, 17(4), pp. 427-439. ISSN 01446193
Abstract
The investigation reported forms part of a wider study into the applicability of design for manufacture (DFM) thinking to the total construction processj and the ways in which this could be implemented. Historical data from change order request procedures were examined for several case studies which were considered to be successful projects. These procedures are intended to capture information about design modifications, and thus can be considered to be analogous to the rework procedures used in manufacturing. It was found that in monetary terms alone, the direct cost of post contract design changes amounts to 5.1-7.6% of the total project cost. Although the case studies used here were a convenience sample, the typical financial opportunity for controlling design changes better is likely to be considerably greater than this. Frequently cited reasons for design changes included: employer has changed his requirements, designer's omission in tender documents and new information on existing site conditions. Little commonality between case studies was found at the work package level. In contrast to manufacturing, the availability and accessibility of data relating to rework is problematic.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | change order; design; design changes; design for manufacture; process mapping |
| Index terms: | project cost, direct cost, case study, mapping, package, designer, design for manufacture, accessibility, tender document, design change, investigation, change order, rework, design modification |
| Subjects: | design changes, contractual arrangements, operations management, tendering, economics, spatial and geospatial analysis, manufacturing engineering, data collection methods, profession, contractual condition, inclusive design |
| Topics: | Project Management, Engineering Principles, Research Practice, Roles and Professions, Procurement, Contract Administration, Design Practice, Cost Management |
| Descriptive scope: | 4 PCEA |
N.B. Descriptive scope is a count of how many of the five facets of empirical research are indicated by the words used in title, abstract and keywords. It is not intended as a judgement on the research; merely a count of the kind of word we would expect to indicate Phenomenon, Concepts, Theoretical framing, Empirical techniques, Analytical techniques. If all five are present, then a code of “5 PCTEA” will indicate this. If you feel the coding for this record is questionable, we welcome discussion around the terms we matched or the way we categorized them. The facet you would expect may not be coded, or a facet may be coded inappropriately. This can also bear on a larger question, of which facets should be treated as defining in construction management research. Please get in touch, and we will look at it. More details here