Mohan M. Kumaraswamy

A comparative study of causes of time overruns in Hong Kong construction projects

Abstract This paper presents the results of a survey undertaken to determine and evaluate the relative importance of the significant factors causing delays in Hong Kong construction projects. The survey covered 83 previously identified delay factors, which were grouped into eight major categories. The main reasons for delays were analyzed and ranked according to different groups classified on the basis of (a) the role of the parties in the local construction industry (i.e. whether clients, consultants or contractors) and (b) the type of projects. Results indicate that the five principal and common causes of delays are: ‘poor site management and supervision’, ‘unforeseen ground conditions’, ‘low speed of decision making involving all project teams’, ‘client-initiated variations’ and ‘necessary variations of works’. Differing perceptions as to the principal causes delaying projects are observed between Hong Kong, Saudi Arabia and Nigeria, the two latter countries being chosen for purposes of comparison with other countries. It is hoped that the significant delay factors identified in this survey will provide a basis for strategies to minimize delays and will also be incorporated into a ‘construction time’ forecasting model for Hong Kong construction projects in the future research programme.

An evaluation of construction time performance in the building industry

Abstract Building industries in many countries have been increasingly recognising the need for more efficient and timely completion of projects. Often, a number of unexpected problems and changes from original design arise during the construction phase, leading to cost and time overruns. Therefore, exploring the reasons for delay is one of the prerequisites of keeping the cost within budget and of good construction time performance. The primary objective of this paper is to identify the principal factors responsible for delays in the Hong Kong building industry, and determine their relative importance as perceived by different participant groups. A questionnaire survey, based on 83 previously identified delay factors, grouped into eight major factor categories, was conducted in early 1995. Responses from 78 construction personnel — from client, consultant and contractor organisations — suggest a strong consistency in perception between clients and consultants, for example as to the importance of the “poor site management and supervision” delay factor and the “contractor-related” delay factor category. However, there was a substantial disagreement between consultants and contractors, as well as between clients and contractors, in respect of the rankings of both the individual factors and the factor categories. Suggestions are given for more effective project management based on the observations. The results of this survey also provide a foundation for further research towards the development of an envisaged “construction time” prediction model for local building projects.

Joint risk management through transactionally efficient relational contracting

The appropriate contracting method and the contract documents for any construction project depend on the nature of the project, but an appropriate contracting method coupled with clear and equitable contract documents do not by themselves ensure project success where people work together in the face of uncertainty and complexity with diverse interests and conflicting agendas. The attitudes of the contracting parties and the co-operative relationships among the project participants are important for successful project delivery. These are examined in the light of transaction cost economics and relational contracting (RC) principles. It is found that RC may well be a useful route towards reduced transaction costs, while also fostering co-operative relationships and better teamwork that in turn facilitate joint risk management (JRM). The usefulness of the latter is reinforced by relevant observations from a recent Hong Kong-based survey, followed by a case study in Mainland China. A basic model is conceptualized for improved project delivery via JRM. This is also seen to be reinforceable by further transactional efficiencies that can be achieved through other RC-based approaches, such as partnering or alliancing.

Contributors to construction delays

Projects can be delayed for a large number of reasons. The third phase of an investigation into such factors focused on the causes of construction delays in Hong Kong. A questionnaire was based on 83 factors identified in previous phases of the investigation. Analysis of the responses reveals differences in perceptions of the relative significance of factors between clients, consultants and contractors. There was general agreement about the relative importance of delay factors such as unforeseen ground conditions. Improving productivity is a useful approach to controlling delays. Important factors affecting productivity itself are thus examined in more depth, with a view to enhancing productivity and reducing delays. The conclusions of this phase of the investigation include a ranking of factors and factor categories that are perceived by different groups of project participants to contribute to delays. For example, higher-ranking factors, such as unforeseen ground conditions, and factor categories such as project-related factors, are found to merit special management attention in countering construction delays. The high degree of disagreement as discerned between the groups of clients, consultants and contractors is indicative of their experiences, possible prejudices and lack of effective communication. It is also confirmed that productivity and other non-scope factors such as effective communications should supplement the project scope factors incorporated into the construction time prediction models that were proposed in the previous phases of this investigation.

Sustainability appraisal in infrastructure projects (SUSAIP): Part 1. Development of indicators and computational methods

Abstract The process of translating strategic sustainability objectives into concrete action at project-specific levels is a difficult task. The multi-dimensional perspectives of sustainability such as economy, society, environment, combined with a lack of structured methodology and information at various hierarchical levels, further exacerbate the problem. This paper (Part 1 of a two-part series) proposes an analytical decision model and a structured methodology for sustainability appraisal in infrastructure projects. The paper uses the ‘weighted sum model’ technique in multi-criteria decision analysis (MCDA) and the ‘additive utility model’ in analytical hierarchical process (AHP) for multi-criteria decision making, to develop the model from first principles. It discusses the development of key performance indicators encapsulated within the analytical model. It concludes by discussing other potential applications of the proposed model and methodology for process automation as part of integrated sustainability appraisal in infrastructure design and construction. Part 2 uses a case study to demonstrate the model application in infrastructure sustainability appraisal at design stages. The paper also discusses the challenges for sustainability research, and gives recommendations.

Delays and cost overruns in the construction projects in the Gaza Strip

Purpose – Delays and cost overruns are evidently frequent problems in the construction industries of many developed and developing countries. The purpose of this paper is to assess factors leading to time overruns (delays) and cost overruns in construction projects in the Gaza Strip. Since there appear to be additional special contributors to delays here, the relative perceptions of contractors, consultants and owners are compared, based on a listing of causal factors derived from previous studies elsewhere, together with other factors arising from special conditions in the Gaza Strip.Design/methodology/approach – A survey of a randomly selected samples yielded responses from 66 contractors, 27 consultants, and 31 owners. The survey included 110 delay factors/causes which were grouped into 12 major groups. The same survey also included 42 cost overrun factors. The level of importance of the delays and cost overrun factors were measured and ranked by their importance indexes, according to the perspectives ...

Developing a decision support system for building project procurement

Abstract The growing need for improved construction procurement and managerial systems, point to the usefulness of a knowledge-based advisory system to help optimise such decisions, amidst the multiplicity of project variables. This new system would harness lessons learnt from past and present research and practice. A Hong Kong based study on a sample of different building projects and professionals, has yielded ‘knowledge’ that has been analysed and structured into pilot/sample core modules of a proposed knowledge-based decision support system. Results from statistical analysis of the data and an Artificial Neural Network model confirmed the value of the proposed system. An extended study to gather more data/knowledge is recommended to further develop the proposed system, using the methodology presented in this paper.

A study of the factors affecting construction durations in Hong Kong

This is the second phase of an investigation into the significant factors influencing construction duration of projects in Hong Kong. The results of the first phase led to the conclusion that larger samples were justified to investigate further the discerned relationships. Expanded samples were obtained in this second phase by adding some reported data from Hong Kong projects to the original surveyed sample. The second phase of this study also further investigates the relationships between different project characteristic variables such as the construction duration, construction cost, total gross floor area and the number of storeys in the case of buildings. Moreover, a case study on plant utilization level and site labour productivity was carried out on a building site to explore the ‘micro-factors’ that affect construction durations. The findings are of importance to all construction industry participants as the derived models help to estimate the construction duration of a project on the basis of signi...

Recent advances and proposed improvements in contractor prequalification methodologies

Abstract Contractor selection is a critical activity that plays a vital role in the overall success of any construction project. An initial cross-sectional survey indicates the wide range of different contractor selection practices followed by various clients around the globe with apparently little interaction or comparisons during their development. A focus on the prequalification approaches (taken here to include ‘registration’) followed by some major public clients in Hong Kong, Australia and USA leads to an interesting overview of recent advances. This focus also highlights some strengths and weaknesses at the critical front-end of the contractor selection process. A proposed new model is developed by the authors for construction contractor prequalification. Finally, the advantages of developing a client advisory decision support system for advising clients on contractor prequalification are discussed, on the basis of the perceived needs and potential knowledge bases that may be tapped for this purpose.

Determinants of construction duration

This paper probes the range of factors affecting construction project duration through a literature review and a pilot survey in Hong Kong. Time-cost models previously proposed in Australia and the UK are compared with data obtained in Hong Kong and similarities are noted. The 111 responses to the detailed questionnaire issued in Hong Kong and the follow-up interviews also indicate other factors that may significantly affect project duration. Of these productivity is examined here, while other factors will be probed in the second phase of this investigation. Time-floor area relationships are also examined and found to be significant. Projects are classified as public or private sector housing and other buildings, roads and other civil engineering projects. Larger samples in each category of construction project will be targeted to test the validity of the models and their parameters in Hong Kong as derived from the pilot survey. It is noted that standardization in public housing projects (as in Hong Kong ...