FAILURE EVENT IN CONSTRUCTION
According to many research shows that there are many failure happen in construction industry. Two of them are research by BRE (Building Research Establishment) and NEDO (National Economic Development Office).
#) The Building Research Establishment (BRE) found that errors in buildings had 50% of their origin in the design stage and 40% 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. The quality-related events were divided into three main areas: “design”, “poor workmanship” and “other”. Design and poor workmanship combined to form more than 90% of the total events listed. Here they are.
1. Aspects of design or project information
– Lack of coordination of design
– Difficult to build
– Design will not work
– Low quality design
– Unclear/missing project information
– Designer does not understand material
2. Aspects of workmanship and site management
– Lack of skill
– Lack of care
– Lack of knowledge
– Poor planning by tradesmen
– Contractor’s organisation problem
– Lack of protection to completed work
Quality performance should be measure by many things, such as:
1. can be considered as either cause for concern or as inevitable events that are part and parcel of the construction process.
2. Whilst some failure items is low some can tremendously affect project time and cost. For a firm to survive, it must not only strive to produce the final product to specification but also at the lowest cost possible. To do so, the failures must be identified and their seriousness assessed.
3. To stay in a highly competitive environment as in the construction industry, not only does quality work have to be offered but also a profit has to be made.
4. Traditional thoughts often have quality and cost running counter to each other. Documentation revealed the opposite to this traditional view. Companies which are capable of reducing cost without sacrificing quality are most likely to offer products/services cheaper, thus, making the product more attractive to the client.
5. It is most convincing if benefits can be shown in terms of cost since costs have a great impact on business. The use of cost as a measure of performance has been recognised and this is usually known as the cost of quality/quality cost.
6. Assessing the cost of a quality system, inspection, prevention and appraisal activities is relatively easy, but the cost of failure is seldom measured. If causes of failure and their associated costs can be identified and reduced, resources can be used for productive work and, cost and time savings will follow.
Quality failure in Civil Engineering project originate in stages such as:
-) project appraisal: failure to recognise the project needs and requirements, and to minimise factors associated with risk, client’s influence, communication problems;
-) design: incomplete information, changes in design, and design mistakes, client’s influence, communication problems;
-) construction: labour, material, subcontractor, plant and equipment, unforeseen conditions and events, project uncertainty, client’s influence, communication problems and poor planning.
Case studies showed that quality improvements and savings came from total quality management techniques and tools that were used to identify high-cost activities which formed the bulk of quality costs. This concept has been developed and used with success in manufacturing – improvement programmes have helped lessened quality costs in service and manufacturing sectors.
Quality cost is usually perceived as either:
-> the cost of managing a quality system, i.e. the cost involved in setting up a quality management system and the periodic costs of auditing by a third-party assessor, or
-> the cost for having a certain level of quality, i.e. quality vs cost trade-off, which shows the relationship of cost at various quality levels, or
-> value engineering, which is concerned with the identification of required functions and development of possible alternatives to fulfil these functions at the lowest possible cost.
Quality cost can be described as all costs associated in managing project quality and costs derived from non-conformances incurred once a project progresses. For example, from the client’s point of view, the more changes that arise from poor planning or ambiguous purpose lead to additional cost. The designer has to spent time reworking drawings or concepts with change or when a mistake is found. Likewise, the construction team has to demolish part of a structure or spend time on rework if quality failures occur.
Quality costs have two major parts. The first is quality management cost comprises prevention and appraisal costs. The second part is failure cost consists of internal failure, external failure and intangible quality costs. This method of classification is known as PAF (Prevention-Appraisal-Failure).
-> prevention – activities that ensures right first time performance
-> appraisal – activities that check whether right first time is achieved
-> failure – activities which result from not conforming to right first time
Quality-related costs in the construction industry as a whole are relatively high in terms of total project cost. For industrial construction in the U.S.A. it was found that more than 12% of the total project cost may be spent on rework. It was estimated that more than 15% of the total project cost was spent on quality cost.
Just remember this:
“You can get rich by preventing defects”
“It’s always cheaper to do the job right first time”
-> Quality management is an important aspect in construction. In this context quality should be defined as conformance to requirements. Project requirements must consider specific quality characteristics for each individual project and be adequately expressed by the client.
-> The management of quality shall start from the appraisal stage and continue throughout the project. It should be the concern of every functional team member to fulfil their role with respect to management of quality.
-> Quality failures in construction projects originate mainly in the design and construction stages. The later a failure is discovered the higher the cost to remedy it. It has been shown that failure costs can be extracted during construction using a matrix. The matrix simplifies the collection of failure costs and highlights problem areas that are hidden under traditional cost control.