Quality monitoring in infrastructural design-build projects : the analysis of an audit-based monitoring system

R. Favie

    Research output: ThesisPhd Thesis 1 (Research TU/e / Graduation TU/e)

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    The roles of stakeholders in traditional construction projects were clear: the client was both responsible and liable for developing a detailed design and specifications and the construction companies had to build in accordance with these specifications. The use of integrated contracts e.g. design-build, is currently more commonplace. In these contracts the construction companies take over the liability and responsibility for the design. This leads to a different type of procurement process, in which private parties are involved at an earlier stage in the project. The shift from traditional to integrated contracts leads to different strategic choices for the client, to a new way of selecting and paying the supplier, and to different quality monitoring strategies. Let us consider this shift in the kind of contracts that are being used in more detail. The construction industry consists of three kinds of works: i) residential buildings; ii) nonresidential buildings; and iii) civil engineering works. Together they represent an estimated output of 1,458 billion euros annually in Europe (forecast 2011). There are five phases in any construction process: i) programme phase; ii) design phase; iii) elaboration phase; iv) realization phase, and v) the use and maintain phase. Traditionally, the client is in charge of the first three phases. Integrated contract types, such as design-build, increase the role of the private companies to both design and realization. The use of integrated contracts requires different choices in the client’s procurement process. These choices are on strategic, tactical and operational levels. During the strategic procurement stage the client decides the extent to which he is willing to work in an integrated contract type by determining the level of supplier integration. Along with this he has to decide how to control the quality of the design and realization to ensure that the requirements are met. These choices determine the kind of quality control during the design and realization phase of the project. During the tactical procurement phase, the client develops the specifications and contracts and selects the suppliers. The suppliers then start their work and the client monitors the quality of this work. There are various ways to monitor and control the quality of a construction project. The use of integrated contract types, such as design-build, requires a different kind of quality control, causing a shift from product-quality check to process-quality control. The difference between product and process control is that product control is designed to detect problems with a product or service, and process control attempts to prevent problems from arising by tweaking the production process so that it inevitably produces a quality product. The literature describes a handful of these quality monitoring systems from a theoretical point of view, but these systems have never been used in practice. As far as we are aware there are, in practice, only four professional monitoring systems that focus on process quality along the lines of the design-build process. Practitioners appear to be satisfied with these systems but their effectiveness and efficiency have not come under scientific scrutiny. One of these systems is the Dutch system-oriented contract management, which is used by the Directorate-General for Public Works and Water Management for all their design-build projects. This system must ensure that the supplier detects defects in good time, takes corrective measures, and evaluates this process. The client’s role shifts from monitoring the product quality to monitoring the quality system. Monitoring is implemented through audits conducted by the client’s representatives. The objective of audits is to determine whether a supplier is competent enough to deal with the project. The audit results are stored in a database and can be used to refine the audit strategy in order to improve control. The present research tests the Dutch quality monitoring system as one example of a process-monitoring system for design-build projects. This is done by answering two research questions: Research question 1: What are the factors that influence supplier compliance in Dutch infrastructural design-build projects? Research question 2: What are the key process characteristics of the monitoring system as implemented in Dutch infrastructural design-build projects? We first analysed the literature to discover the factors that influence supplier compliance with the monitoring system. This leads to a framework consisting of Critical Success Factors (CSFs) for construction projects. Five factor groups were indicated in the literature: a) supplier-related factors; b) client-related factors; c) project-related factors; d) external factors, and e) the state variables (supplier capabilities). We then conducted interviews with experts from the civil engineering field to adapt the framework for use in infrastructural design-build projects. To determine the factors that influence supplier compliance (first research question) and the key characteristics of the monitoring system (second research question), we collected empirical data from a large infrastructural project in the Netherlands. This project consisted of approximately 5,500 audit checks performed in the period 2006-2009 by 70 auditors in 57 different subprojects. We enriched the data through additional interviews, desk research and smaller surveys, and collected additional information about the 11 suppliers that were involved in the projects, the 57 subprojectss, the external factors, the state variables and the auditors. This resulted in a database that could be used to answer the two research questions. The analysis of our database started with bivariate analysis between the audit outcome and several single independent variables taken from the CSF framework and auditrelated. This gave a first impression of the data and the possible factors related to the audit outcomes (compliance or non-compliance). For example, we found a higher proportion of non-compliance for road construction than for the other types of work (general works, electrical works, environmental works and structural works). We also found a higher proportion of non-compliance for the road construction companies, the projects in which contract amendments were made, and the projects that were not common for the suppliers. We also found a higher proportion of non-compliance for audit checks related to safety issues and audit checks related to the functioning of the supplier’s quality management system. We also found that over time, the proportion of non-compliance decreases and that there are differences between the different auditors if we looked at their backgrounds. To gain a deeper understanding of the bivariate findings we conducted a series of multivariate analyses to investigate possible explanations for these findings with our data. For instance, we found that we could explain the high proportion of non-compliance for road construction companies by the fact that they had more problems with their design tasks. After these analyses we conducted a survey in which we asked experts to predict several of our findings. This showed that the experts’ intuition about the system as a whole differs markedly from our actual findings. We concluded that our research contributes to the current state of affairs in at least four ways. The first addition is knowledge about quality monitoring in infrastructural designbuild projects as part of the procurement process. The ten procurement steps that we described are a good representation of what should be done to develop a successful infrastructural construction project. The second contribution is the knowledge about the key characteristics of the quality monitoring process that we gained by analysing 5,500 audit checks. This knowledge can help to improve the monitoring system by making it more efficient and effective. The analysis also provided a number of interesting empirical insights, such as inexplicable lower compliance levels among suppliers in August. These insights are the third contribution. The fourth and final contribution is a test considering the influence of Critical Success Factors on supplier compliance suppliers in design-build infrastructural works. We used CSFs from the literature and tested them with our data. For approximately half the factors that were indicated in the literature we did not find an influence on supplier compliance. Since our research is the first that we know of that uses actual empirical project data, this casts doubt on the findings in the existing literature that were all based on expert interviews. The results of our own survey confirm these doubts.
    Original languageEnglish
    QualificationDoctor of Philosophy
    Awarding Institution
    • Built Environment
    • Maas, Ger, Promotor
    • Snijders, Chris C.P., Promotor
    Award date8 Dec 2010
    Place of PublicationEindhoven
    Print ISBNs978-90-6814-634-9
    Publication statusPublished - 2010

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