Russell, M M; Liu, M; Howell, G and Hsiang, S M (2015) Case studies of the allocation and reduction of time buffer through use of the last planner system. Journal of Construction Engineering and Management, 141(2): 04014068, ISSN 0733-9364
Abstract
Buffers are used in construction to absorb variation caused by the inherent complexity and uncertainty present in construction projects. The case studies presented here focus on time buffer added to construction task durations. For this research, time buffer is defined as extra time added during planning to individual task durations to compensate for uncertainty and protect against workflow variation. Two case studies were conducted with one involving a mechanical contractor and the other involving a large general contractor. This research contributes to the body of knowledge by: (1) investigating the time buffer impact on project performance; (2) empirically demonstrating the effect of last planner system (LPS) on reducing time buffer and increasing percent planned complete (PPC); and (3) examining the buffer trends of different trades and activity types. The findings demonstrate LPS as an example of an effective planning strategy for construction managers in improving project performance and help them understand what drives the need for buffer in their construction schedules, allowing efforts focused on strategically addressing the most critical areas of concern and uncertainty.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | buffer; labor and personnel issues; planning; uncertainty |
| Index terms: | case study, PPC, buffer, project performance, duration, personnel, time buffer, general contractor, strategy, last planner system, variation, construction project, construction manager, body of knowledge, workflow, complexity |
| Subjects: | management, project management theory and practice, financial risk, production management, contractual condition, project controls, systems engineering, standard forms of contract, data collection methods, profession, practitioner, operations research, knowledge management |
| Topics: | Contract Administration, Time Control, Human Resources, Procurement, Roles and Professions, Engineering Principles, Information Management, Research Practice, Project Management, Cost Management, Business Strategy |
| Descriptive scope: | 3 PCE |
N.B. Descriptive scope is a count of how many of the five facets of empirical research are indicated by the words used in title, abstract and keywords. It is not intended as a judgement on the research; merely a count of the kind of word we would expect to indicate Phenomenon, Concepts, Theoretical framing, Empirical techniques, Analytical techniques. If all five are present, then a code of “5 PCTEA” will indicate this. If you feel the coding for this record is questionable, we welcome discussion around the terms we matched or the way we categorized them. The facet you would expect may not be coded, or a facet may be coded inappropriately. This can also bear on a larger question, of which facets should be treated as defining in construction management research. Please get in touch, and we will look at it. More details here