Understanding Flow and Micro-Variability in Construction: Theory and Practice

Irina Brodetskaia1 & Rafael Sacks2

1PhD Candidate, Faculty of Civil and Env. Engineering, Technion – Israel Institute of Technology, Haifa 32000, Israel Phone +972-4-8292875, cvirina@techunix.technion.ac.il
2Senior Lecturer, Faculty of Civil and Env. Engineering, Technion – Israel Institute of Technology, Haifa 32000, Israel Phone +972-4-8293190, cvsacks@techunix.technion.ac.il

Abstract

Uncertainty within supply chains, design changes, and lack of predictability of the production capacity of subcontracting trades, are only a few of the factors that make construction projects unpredictable. For residential finishing works, this is true even at the daily level; however most available production control methods, such as Last Planner, do not operate at this resolution. As a result, a production system is needed in which intelligent decisions about effective utilisation of available resources can be made daily or even hourly. A theoretical understanding is needed of the flow of operations on the micro-level of project management – at the level of daily resource utilisation – in order to develop appropriate systems. Various models of process flow developed in manufacturing industries for management of production on the operational level, which might apply to construction, are presented and discussed. A detailed case study, in which the patterns of flow of finishing trades were observed and recorded in a large residential project, provided a basis for exploration of different models. The patterns of flow of trade crews through the building demonstrate reentrant flow similar to that found in semiconductor job shop situations, but also exhibit differences and contradictions with the main assumptions of factory production management. Heuristic solutions appear to hold promise for guiding the flow of construction crews at the daily operational level if and when conditions emerge that invalidate work packages assigned in a weekly work plan.

Keywords

Micro-variability, production flow, project management, resource utilisation, trade

Files

Reference

Brodetskaia, I. & Sacks, R. 2007, 'Understanding Flow and Micro-Variability in Construction: Theory and Practice' In:, Pasquire, C.L, C.L. & Tzortzopoulos, P., 15th Annual Conference of the International Group for Lean Construction. East Lansing, Michigan, USA, 18-20 Jul 2007. pp 488-497

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