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The purpose of this study is to identify the primary root causes of defects in terms of why they persist in construction, despite the increasing implementation of quality systems. Defects in construction continue to be a source of concern in the construction industry. There have been studies that have tried to identify causes of defects. Although concepts are usually related to organisational factors, previous studies have been carried out on an operational level. There is a well-trodden area within the literature relating to the operational level, but little is known about the causes of defects on a higher, organisational level within construction.

A new approach based on the notion of process causality and the use of cognitive mapping has been adopted. The aim was to take a step back and unravel causes of defects in the execution of construction projects. From workshops with representatives drawn from different parts of the industry, themes have been identified and investigated from a causation perspective.

It was found that the causes of defects mainly reside in endogenous factors within organisations as opposed to execution failure or exogenous factors related to market, material or equipment behaviour.

More specifically, it was found that the dominant cause of defects lies within organisational shortcomings, suggesting that improvements can be found on the management and strategic levels within projects instead of on the operational level.

The four sections to this article have distinct but inter‐related objectives. Part I introduces the concepts, problems and tensions central to an understanding of the product liability debate. These issues recur throughout the article. Part II outlines the development of product liability law in Europe and assesses the impact of the European Directive on Product Liability. The “product liability crisis” in the United States is discussed in Part III, which looks at the law's development and proposals for reform. In Part IV the United States and European positions are compared and the case is made out for a global uniform product liability law which recognises the social responsibility of the producer towards those injured by his products.

The successive Malaysian government aims to provide housing to households earning the median income and below. However, there has been continuous criticism and complaints from the media and literature on the magnitude of the defects in affordable housing. Therefore, this research has investigated the defects in affordable housing for the users’/occupants' perspectives.

With a response rate of 69%, the research developed a questionnaire instrument that included twenty-one defects in buildings based on literature and observation. These were scored on a 5-point Likert scale ranging from very common to least common. Twelve causes of defects measured on a five-point scale were included in the survey. Thirteen additional items that had to do with remedial actions to reduce defects were included. These were scored on a 5-point Likert scale ranging from strongly agree to least agree. The survey forms were administered to all the 152 home occupants in a Program Perumahan Rakyat (PPR) housing estate through hand delivery in a northern state in Malaysia.

The data revealed that broken doors, damaged roofs, damp walls and broken tiles in rooms were the most common defects in the housing development. It was found that defects in the buildings were caused by poor workmanship, defective materials, poor designs and bad weather. Additionally, to rectify the defects, adequate supervision is required during maintenance, the repairs must be conducted on time and there is a need to have competent maintenance organisations. Through factor analysis, the 21 defects were structured into six factors, the 12 causes were grouped into 5 factors and the 13 remedial actions were grouped into 6 factors.

The information on the nature, degree and kinds of defects from the users' perspectives will dictate when repair work is to be undertaken and allow future work to be programmed and financed as part of a maintenance rolling programme.

This research focused specifically on “Program Perumahan Rakyat” housing development. Furthermore, none of the previous research on defects conducted attempted to categorise the defects in the buildings. The categorisation is very important for systemic decision-making because there are continuous interactions amongst the defects, causes and remedial actions.

One major problem preventing further application and benefits from additive manufacturing (AM) nowadays is that AM build parts always end up with poor geometrical quality. To help improving geometrical quality for AM, this study aims to propose geometrical deviation identification and prediction method for AM, which could be used for identifying the factors, forms and values of geometrical deviation of AM parts.

This paper applied the skin model-based modal decomposition approach to describe the geometrical deviations of AM and decompose them into different defect modes. On that basis, the approach to propose and extend defect modes was developed. Identification and prediction of the geometrical deviations were then carried out with this method. Finally, a case study with cylinders manufactured by fused deposition modeling was introduced. Two coordinate measuring machine (CMM) machines with different measure methods were used to verify the effectiveness of the methods and modes proposed.

The case study results with two different CMM machines are very close, which shows that the method and modes proposed by this paper are very effective. Also, the results indicate that the main geometrical defects are caused by the shrinkage and machine inaccuracy-induced errors which have not been studied enough.

This work could be used for identifying and predicting the forms and values of AM geometrical deviation, which could help realize the improvement of AM part geometrical quality in design phase more purposefully.

Most residential building owners often report problems associated with the plumbing systems. If identified at the early stages, plumbing-related defects can be easily repaired. However, if unnoticed for a long period of time, they could lead to major damages and incur a significant cost to repair. Despite the problems, studies investigating plumbing anomalies and their root causes in residential buildings are limited. This study aims to explore plumbing defects and their potential causes, diagnosis methods and repair techniques in residential buildings.

This research used data collected through an extensive survey of both academic and grey literature. Through the content analysis, plumbing defects and the associated causes have been identified and presented in tabular format.

The study investigated the anomalies and causes in the residential plumbing system under five key sub-systems: water supply system; sanitary plumbing system; roof drainage system; heating, ventilation, air conditioning and gas system; and swimming pool. Accordingly, some of the identified plumbing defects include leakages, corrosion, water penetration, slow drainage and cracks. Damaged pipes, faulty equipment and installations are some of the common causes of the anomalies. Visual inspection, hydrostatic pressure test, thermography, high-tech pipe cameras, infrared cameras, leak noise correlators and leak loggers are techniques used for diagnosing anomalies. Reactive, preventive, predictive and reliability-centred maintenance strategies are identified to control or prevent anomalies.

The findings of this research can be used as a useful tool or guideline for contractors, plumbers, facilities managers and building surveyors to identify and rectify plumbing system-related defects in residential buildings.

Construction defects are one of the primary causes of deficient quality performance and constantly yield project cost and schedule overruns mostly because of rework. This study aims to propose a new method for identifying a bespoke checklist of the most recurrent defects in residential construction work and their correlated causes as a basis for developing a framework for practical improvements in managing defect risks.

A literature review was first used to ground the defects within the existing theory and develop a new framework for ranking the key defects involved. This was demonstrated and tested by an analysis of Queensland Building Construction Commission (QBCC) archival data for 42,000 reported defects in new Queensland residential buildings. A questionnaire survey of 427 construction practitioners from 37 trades was then conducted to determine their causes.

The developed framework consists of preconditions for defective acts, defective supervision and organizational influences and is found to be suitable for analyzing the QBCC archives to rank the 20 most frequent defects. In the demonstration study, a questionnaire survey identified the highest frequency latent causes of defective acts to be workers taking shortcuts to complete tasks, workers’ lack of skill or knowledge level, challenges and limitations of technical constructability, and incorrect material supply; the failure to correct a known problem and poor supervision for defective supervision; and inadequate employee training, low managerial priority for quality and high time pressure and constraints for organizational influences.

The method is a new approach to identifying the key defects in residential construction work and their correlated causes for developing bespoke checklists as an aid to in managing defect risks.

AN exceedingly careful control of the surface of aero‐engine parts has beyond doubt become an excellent habit both with manufacturers and those who are to use the engine. A crack on a new part, or one which will cause a fatigue failure in work—these are the defects looked for by inspectors during manufacture, overhaul, or repairs. Cracks are very frequent causes of accidents and this fear often underlies the rejection of parts which are only suspect but which might work quite well until normal wear and tear would cause them to exceed permissible tolerances. In many cases, electro‐magnetic examination or etching reveal defects on the surface of engine parts which cannot be defined: in such cases, for the sake of certainty the part is rejected on the ground that it is cracked or made from faulty material.

Since works-in-process (WIPs) are highly vulnerable to defects because of the variety and complexity of manufacturing processes, the purpose of this paper is to describe how to utilize existing analytics techniques to reduce defects, improve production processes, and reduce the cost of operations.

Three alternatives for diagnosing causes of defects and variations in the production process are presented in order to answer the following research question: “What are the most important factors to be included in prognostic analysis to prevent defects?”

The key findings for the proposed alternatives help explain the characteristics of defects that have a great impact on manufacturing yield and the quality of products. Consequently, any corrective action and preventive maintenance addressing the common causes of defects and variations in the process can be regularly evaluated and monitored.

Although the focus of this study is on improving shop-floor operations by reducing defects, further experimentation with business analytics in other areas such as machine utilization and maintenance, process control, and safety evaluation remains to be done.

This study has been validated with several scenarios in a manufacturing company, and the results demonstrate the practical validity of the approach, which is equally applicable to other manufacturing sub-sectors.

This study is different from the others by providing alternatives for diagnosing the root causes of defects. Control charts, costs of defects, and clustering-based defect prediction scores are utilized to reduce defects. Additionally, the key contribution of this study is to demonstrate different methods for understanding WIP behaviors and identifying any irregularities in the production process.

This paper discusses some basic ideas about process development and control in Part I and applies them to soldering in Part II. Because it is possible to understand how design, materials and process affect the product, it is unnecessary and inappropriate to resort to the statistical‐correlation methods that are applied to complex processes. A process qualifies for the label ‘closed loop’ only if the design and materials going into.it are controlled. The types, degree and sophistication of control needed for a process are to be judged by consistency of the product. For soldered assemblies, the product is evaluated by visual inspection, and the adequacy of process development and control depends on the adequacy of inspection. Inspection can be improved if it is regarded as a process. It can also be improved if inspectors understand which features are important and which can be ignored safely, i.e., by understanding their causes and associated risks. Much of the criticism of visual inspection, and perception of need for automated inspection, derive from a failure to distinguish clearly enough between material and process variables, between the two types of inspection (product‐oriented and materials/process‐oriented) and between appearance and risk. Properly controlled visual inspection is well suited for evaluating the soldering process. The most important visual attribute to look for in solder inspection is the contour of the fillet, because this is what reveals the quality of wetting, and wetting is the most important physical attribute of the connection in determining its strength and reliability. Wetting depends on just two basic requirements, heat transfer and solderability, and these are discussed in some detail. Causes of non‐ideal texture and lustre of the solder are given, but these attributes do not affect reliability, nor is measuring solder purity important. Additional factors which do affect reliability relate more to design and materials than to process. Failure to deal with these factors can result in solder defects that are undetectable by any inspection technique. The answer to this problem is therefore not automated inspection to find more kinds of defects than visual inspection can, but control of design and materials, as well as process, to prevent them entirely.

This paper covers the development of a novel defect model for concrete highway bridges. The proposed defect model is intended to facilitate the identification of bridge’s condition information (i.e. defects), improve the efficiency and accuracy of bridge inspections by supporting practitioners and even machines with digitalised expert knowledge, and ultimately automate the process.

The research design consists of three major phases so as to (1) categorise common defect with regard to physical entities (i.e. bridge element), (2) establish internal relationships among those defects and (3) relate defects to their properties and potential causes. A mixed-method research approach, which includes a comprehensive literature review, focus groups and case studies, was employed to develop and validate the proposed defect model.

The data collected through the literature and focus groups were analysed and knowledge were extracted to form the novel defect model. The defect model was then validated and further calibrated through case study. Inspection reports of nearly 300 bridges in China were collected and analysed. The study uncovered the relationships between defects and a variety of inspection-related elements and represented in the form of an accessible, digitalised and user-friendly knowledge model.

The contribution of this paper is the development of a defect model that can assist inexperienced practitioners and even machines in the near future to conduct inspection tasks. For one, the proposed defect model can standardise the data collection process of bridge inspection, including the identification of defects and documentation of their vital properties, paving the path for the automation in subsequent stages (e.g. condition evaluation). For another, by retrieving rich experience and expert knowledge which have long been reserved and inherited in the industrial sector, the inspection efficiency and accuracy can be considerably improved.