Søren Munch Lindhard

Factors Affecting Schedule Delay, Cost Overrun, and Quality Level in Public Construction Projects

AbstractAs a result of the loss of financial resources and the need to optimize projects, academics, politicians, and the construction industry have become increasingly aware of the challenges presented by the frequent time and cost overruns and reduced quality of construction projects. The purpose of this study was to analyze the factors that project managers experience as having the greatest effect on time, cost, and quality, and to discover whether the effects of these factors are significantly different from each other. A questionnaire with 26 factors identified from interviews was sent to the full population of publicly employed project managers. Factors were ranked using the relative importance index and tested for significant differences using Friedman’s test. Wilcoxon’s test was used in a post-hoc analysis. From the findings it was determined that the most influential factor for time is unsettled or lack of project funding; for cost, errors or omissions in consultant material; and for quality, err...

Scheduling of large, complex, and constrained construction projects – an exploration of LPS application

Scheduling of construction projects is by nature complex. The construction process is unreliable and difficult to forecast. Last planner system (LPS) is introduced in construction in order to achieve greater reliability and productivity in the process. To ensure that implementation is successfully anchored in the organisations, differences between theory and application are investigated. To determine the theoretically correct application a literature survey is conducted. A questionnaire survey is made to collect empirical date of the practical application. Comparison between theory and application revealed that often only parts of LPS are applied. A partly applied LPS can be a main barrier to increased reliability in the scheduling process. Furthermore, the questionnaire showed that failures in the execution processes often start in the look-ahead plan. Here, lacking knowledge of the execution process is causing problems to be overlooked. To increase the level of knowledge foremen should be involved in the look-ahead planning.

Exploration of the reasons for delays in construction

Construction sites are dominated by chaos and complexity, enforcing challenging conditions for establishing reliable and robust schedules that are easy to observe. The consequence is a large amount of delayed activities that again results in an unreliable schedule. Last planner system (LPS) was introduced as a production planning and control system to increase the reliability of scheduling task. By focusing on the removal of constraints, the LPS has successfully decreased the number of delayed activities. To further decrease delays, this research investigates the causes for delays at three construction cases. In total, 5424 scheduled activities were followed, whereof 1450 were delayed. The delayed activities were, besides the unidentified ones, categorized into 11 different categories and a statistical test of means was performed. The research revealed six often-occurring causes to delay: connecting work, change in work plans, workforce, external conditions, material and construction design. Furthermore, the study revealed five seldom-occurring causes to delay: space, equipment, rework, unexpected conditions, and safety. The findings have been structured in accordance to the preconditions used in the LPS theory. Therefore, the results can directly be applied to the making-ready process and used as guidance of where to intervene in attempt to reduce future delay.

On the Road to Improved Scheduling: Reducing the Effects of Variation in Duration

Scheduling in onsite construction is based on commitments. Not kept commitments are resulting in non-completions which lead to waste. Moreover, it is important that commitments are made realistic to avoid both positive and negative variation in duration. Negative variation is destructive to plans and schedules, and is resulting in delays; while positive variation is destructive to productivity by creating unexploited gap between activities and thus inducing unexploited capacity. By registering non-completion at three construction sites, the magnitude of activities inducing negative variation has been mapped. In total 5424 activities has been registered whereof 1450 activities ended up as non-completions; thus, did 27% of the scheduled activities not finish on scheduled. Both positive and negative variation can be minimized by improving the quality of the commitments. Moreover, positive variation can be exploited by A) ensuring that the crew finishing an activity to early can continue their work and B) ensuring that any connecting activity can start as fast as possible.

Identifying the key process factors affecting project performance

Purpose A construction project traditionally involves a variety of participants. Owners, consultants, and contractors all have diverse opinions and interests, but they all seek to ensure project success. Success is habitually measured as performance output regarding cost, time, and quality. Despite previous research mapping the success and failure factors, construction managers seem to have difficulty in attaining success. To provide clearer guidance on how to fulfill success criteria, the purpose of this paper is to identify the underlying factors that affect performance and thus project success in construction processes. Design/methodology/approach A questionnaire survey based on a literature review provided 25 key process factors divided into five key categories. Based on the responses from commonly involved construction parties, the factors were ranked and tested for significant differences between the parties. Findings The top five most important process factors were found to relate to the sharing of knowledge and communication. Moreover, testing the ranking for significant differences between owners, consultants, and contractors revealed five differences. The differences related to the interpretation and importance of trust, shared objectives, project coordination, and alternative forms of coordination. Originality/value All respondents identify improved knowledge sharing and communication as the key to improved cost, time, and quality performance and are therefore the areas where construction managers need to focus their resources. Thus, improved experience sharing and communication will increase the likelihood of project success, through improving competences, commitment, and coordination.

A Lean Framework for Production Control in Complex and Constrained Construction Projects

Production conditions in construction are different than in the manufacturing industry. First of all, construction is rooted in place and conducted as on-site manufacturing. Secondly, every construction project is unique and a one-of-a-kind production, managed by a temporary organization consisting of several companies. Thirdly, highly interdependent activities have to be conducted at limited space, with multiple components, a lack of standardization, and with many trades and subcontractors represented on site. This interrelation results in a production where different contractors perform interacting and overlapping activities. This increases uncertainty and make the construction process very difficult to plan and control. Additionally, a lot of unpredictable factors (e.g. climate conditions) affects control, and makes construction even more complex. Production control is an essential part of any complex and constrained construction project. Even though several tools have attempted to add structure and to create order, to the complex, dynamic, and uncertain context in which constructions is conducted, none has yet fully succeeded in providing a robust production control system. With outset in the lean tool Last Planner System of Production Control, a robust construction production control framework has been developed.

Mass Customization in the Building and Construction Industry

Recent research shows that the productivity in the Danish construction industry has only doubled since 1966, which is significantly less compared to other sectors in Denmark. However, increasing industrialization has achieved results in other industries in Denmark in terms of increasing productivity.

Analyzing Factors Affecting Time, Cost, and Quality between Diverse Public Construction Agencies

Construction projects’ overrun of deadline and budget with reduced quality of the end-product is a challenge which academics, politicians, and construction parties have become more aware of. The objective of this research is to review if factors affect public construction projects’ time, cost and quality significantly different between different public construction agencies. The study was initiated by literature review and expert interviews, which lead to identification of 26 factors. A questionnaire was afterwards sent to the full Danish population of publicly employed project managers. The principal findings demonstrate that factors affecting time, cost and quality to a large extent do not differ significantly between the studied organizations. However, a significant difference between factors impact at time, cost and quality was established in the following post-hoc analysis. The conclusion is thus consequently, that the identified factors largely affect non-significantly different between organizations.

Handling and Reducing Variation in On-site Production

Variation is undesirable in a production system because it complicates production management. Variation caused by completing activities too early (positive variation) or too late (negative variation) is studied through a questionnaire survey where focus was on how to reduce or handle this variation. It was found that the top initiatives to handle variation were: mutual core values, collaboration, process transparency, control of interdependencies and schedule robustness while the top initiatives to reduce variation were: collaboration, output quality, and buffering, standardization, and multi skilled craftsmen. The results are compared and discussed according to the construction control principles Last Planner System (LPS). LPS is found to focus on removing negative variation to improve the efficiency of the planning system. Therefore, LPS has only minor focus on the actual process, on communication and collaboration on-site, on how the process is managed by the construction managers in relation to mutual core values, leadership and motivation, and on the quality of the production output.

Incentive Agreements and Long Lasting Partnerships as Instruments to Create Continuous Improvement

Incentive agreements or bonus schemes are contractual supplements known from partnering. Contractual commitment is ensured by using on-site performance as a parameter to calculate the contractual payment. The research is conducted as a case study of a public water board. Data collection consisted of interviews which are supplemented with archived data. The public water board uses turnkey contracts designed as 6 years contracts with a fixed price and an integrated yearly regulation of negative 2 % of the contractual value and supplemented with incentive and bonus schemes. The Incentive agreements and bonus schemes are related to economics, quality, energy and environment, and customer satisfaction all regulated with 2 % pr. year to ensure continuous improvement. The effect of the incentive and bonus schemes is followed revealing a positive result; in 2012 82.5 % of the possible bonuses were released. Moreover, the long lasting partnerships are ensuring a positive environment for professional discussion and learning, thus it is important to avoid staff changes.