1、Capturing the Cost of Quality Failures in Civil Engineering Hamzah Abdul-Rahman (University of Manchester Institute of Science and Technology) INTRODUCTION One reason which relates quality (conformance to requirements) to a firms survival, is increased customer expectations an organization must prov
2、ide the products/services to fulfill the requirements of the clientl. Another is the costs incurred due to operation and product failures； a firm should not spend more than what is normally required to meet the clients requirements； this is especially true in the present competitive market. These co
3、sts, known as quality costs, are known to be capable of reduction in repetitive processes and in the controlled environment of manufacturing industries. The usefulness and importance of knowing the cost of quality in manufacturing is well known. This is not so in the construction industry. Since the
4、re are differences in the nature and haracteristics of the processes and environments of the two industries, it is difficult to assess whether similar quality cost concepts can be used in construction. One can only speculate that if the manufacturing and service industries can benefit from quantifyi
5、ng quality costs then there should also be benefit to construction. Theoretically it seems easy to apply the quality costs concepts into the design and construction phases of a civil engineering project. In practice, it is quite complex and can be difficult. This article attempts to address the conc
6、ept of quality cost, especially as an aid to identifying and reducing failures during construction of civil engineering projects. The aims of this article are to: (1) generate an awareness of the design-and-construction caused failures； (2) provide an insight into the potential of using quality cost
7、 in civil engineering construction； (3) illustrate by a case study how failure costs can be captured and used in a civil engineering contract； (4) recommend that quality cost information be used in managing civil engineering works. FAILURE EVENTS IN CONSTRUCTION The Building Research Establishment (
8、BRE) found that errors in buildings had 50 per cent of their origin in the design stage and 40 per cent in the construction stage. In a National Economic Development Office (NEDO) survey, aimed at improving methods of quality control for building works, some 501 quality related events were noted. Th
9、e quality-related events were divided into three main areas: design, poor workmanship and other. Design and poor workmanship combined to form more than 90 per cent of the total events listed in Table I. Under poor workmanship lack of care and lack of knowledge were the main causes, whilst in design
10、unclear/missing information and design will not work were identified as the major causes of problems, including the most serious cases. NEDO showed that causes of defects in housing were mainly in design (50 percent) and construction (30 per cent). The remaining 20 per cent were attributed to materi
11、als and other causes. WHY QUALITY PERFORMANCE SHOULD BE MEASURED IN CONSTRUCTION Although the above findings reveal failures in building projects, failures among civil engineering projects may be even more serious owing to the greater variety of risk factors. The findings above can be considered as
12、either cause for concern or as inevitable events that are part and parcel of the construction process. It is well-known that, while the frequency of some failure items is low, they can tremendously affect project time and cost. For a firm to survive, it must strive not only to produce the final prod
13、uct to specification but also to produce it at the lowest cost possible. There is no doubt that most firms, whether in design or construction, are able to produce work to the specification within an acceptable tolerance with respect to time and costs. The magnitude of the tolerance has to be reduced
14、 for a firm to remain competitive. Management and production teams must reduce failures that are quality-related to the minimum such that there is a reduction in the tolerance gap. In order to do this, the failures must be identified and their seriousness assessed. In construction, many companies ha
15、ve taken up Quality Assurance (QA) as a means of staying in business. Designers, consultants, contractors and even subcontractors are aware of the consequences if they fail to provide a minimum level of assurance to their clients. However, to stay in a highly competitive environment as in the constr
16、uction industry, not only does quality work have to be offered but also a profit has to be made. Traditional thoughts often have quality and cost running counter to each other. Documentation on quality management achievements reveals the opposite to this traditional view. Companies which are capable
17、 of reducing cost without sacrificing quality are more likely to offer products/services more cheaply, thus making the product more attractive to the client. This is another reason for measuring quality. The measurement of performance in managing quality can take many forms. However, it is most conv
18、incing if benefits can be shown in terms of cost since costs have a great impact on business. In quality management the use of cost as a measure of performance has been recognized and this is usually known as the cost of quality or quality cost. While it is relatively easy to assess the cost of impl
19、ementing a quality system, inspection costs and other costs related to prevention and appraisal activities, the cost of failure in construction processes are seldom measured. If causes of failure and their associated costs can be identified and reduced, resources can be used for productive work, and
20、 cost and time savings will follow. SOURCES OF QUALITY FAILURE Quality failures in a civil engineering project originate in stages such as: project appraisal: failure to recognize the project needs and requirements, and to minimize factors associated with risk, clients influence, communication probl
21、ems； design: incomplete information, changes in design, design mistakes, clients influence, communication problems； construction: labor, material, subcontractor, plant and equipment, unforeseen conditions and events, project uncertainty, clients influence, communication problems and poor planning. During the appraisal stage, the functional needs of the project are investigated and identified. In order for these needs to be accurately translated into information for decision making, the
