Research output: Book/ReportPh.D. thesis

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This PhD thesis contains the results of a three year research process carried out at Department of
Mechanical and Manufacturing Engineering at Aalborg University. The thesis is entitled “Exploring the Last
Planner System in the Search for Excellence” and does together with the appended published papers serve
as documentation for the conducted research. The research topic has been scheduling of on-site
construction with focus on improving the lean based production control tool Last Planner System (LPS).
The research topic was chosen due to today’s production control systems’ inadequacy of handling the
complexity of on-site construction. Today’s production control systems’ inadequacy has resulted in
numerous of cost and time overruns. Even though LPS is reported to have a positive effect on schedule
reliability, improvements are still possible. Therefore, the current state of LPS has been explored both
regarding the theoretical comprehension and the on-site application. To create the theoretical foundation a
literature survey was conducted. On-site application was examined through three different studies. 1) A
questionnaire survey added to create an appreciation of knowledge to, and application of, LPS in the
industry. 2) Four case studies were conducted to increase the richness and depth to the data and thus gain
a more colorful insight into production control and scheduling on-site. Archive data of non-completions
made it possible to extract quantitative data and to make statistical hypothesis testing. 3) Three interviews
with site-managers. The interviews were used to capture the site-managers’ experience, attitudes, and
opinions in relation to production control with focus on scheduling.
Based on the collected data, LPS was analyzed. The analysis revealed several points of criticism and
suggestions to areas where LPS can be improved. Key critiques to the existing LPS were that it is based on a
closed system view, where the surrounding world not is considered, that leadership and motivation of
project participants is disregarded, that the Critical Path Method (CPM) is ignored, that there is only a
limited interest for flows, that the making ready process not is considering the quality of the fulfillment,
that variation in soundness occurs, that LPS does not incite communication and collaboration on-site, and
finally that the output quality is not considered in the follow-up phase.
As an answer to the revealed critiques a new framework for production control was developed. By
adopting an open system-theory mindset the surrounding world including motivation and leadership is now
considered. The surrounding world is important because it affects both processes and behavior on-site
which together are having a great impact on the quality and quantity of the output. The existing criteria
(duration and interrelationships) for selecting activities have been expanded to include flow and CPM
considerations, to increase schedule quality. The making ready process is changed to include both the
presents and the quality of the fulfillment. Hence, optimal fulfillment is pursued. A health check of buffered
activities is added to handle variation in sound activities and to avoid non-ready activities in entering the
Commitment Plans. In the search for improved on-site communication and collaborations a Coordination
Schedule is implemented at the Commitment Plan level. Finally, the follow-up phase now includes an
evaluation of both output quantity and quality to increase management’s insights to the progress of the
construction site. All changes have been evaluated by interviewing seven experts. The experts were
interviewed to refine the adjustments and to add validity to the new framework. A full description of the
new production control framework can be found in chapter 3 Exploring for excellence within Last Planner
Original languageEnglish
PublisherInstitut for Mekanik og Produktion, Aalborg Universitet
Number of pages217
ISBN (Print)87-91464-53-6
Publication statusPublished - 2013

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