REMOVING HIDDEN WAITING TIME IN CRITICAL PATH SCHEDULES: A LOCATION-BASED APPROACH TO AVOIDING WASTE

Production waste from non-productive activities is a well understood concept in Lean Construction Management. Waiting-time is also a well understood form of production waste. However, waste arising from the hidden waiting-time inherent in poorly designed CPM schedules has not previously been described. Hidden waiting-time is defined and demonstrated using location-based visualisation methods for construction cycles. A construction cycle refers to a repetitive sequence of work required to erect a structure. Two case studies illustrate how such waiting time can be removed and replaced by production buffers using appropriate levels of location breakdown. What sort of waste is represented by the time reduction demonstrated in these case studies? The TFV based taxonomy of wastes includes both inefficient waste and waiting time, but combining the two to define hidden waste found in CPM schedules, requires a new category. Cycle waiting time is the waste of not planning the most efficient project structural cycle and therefore not being able to identify hidden wastes based on utilisation of location based structure.

[1]  Gregory A. Howell,et al.  Capacity Utilization and Wait Time: A Primer for Construction , 2001 .

[2]  Tariq S. Abdelhamid,et al.  Analyzing the Relationship Between Production Constraints and Construction Work Flow Reliability: An SEM Approach , 2010 .

[3]  Luiz Fernando Mählmann Heineck,et al.  Data Envelopment Analysis and the Quest for Targets – a Case Study in Connection to Waste Reduction on Site , 2014 .

[4]  Trond Bølviken.  10 Statements on Production and Construction Theory , 2006 .

[5]  Russell Kenley.  Dispelling the Complexity Myth: Founding Lean Construction on Location-based Planning , 2005 .

[6]  Burcu Akinci,et al.  Proactive Approach for Reducing Non-Value Adding Activities Due to Time-Space Conflicts , 1998 .

[7]  Sven Bertelsen,et al.  Lean Construction: Where Are We and How To Proceed? , 2004, Lean Construction Journal.

[8]  Søren Wandahl,et al.  The robust schedule - a link to improved workflow , 2012 .

[9]  Olli Seppänen,et al.  Location-Based Management for Construction: Planning, scheduling and control , 2006 .

[10]  Lauri Koskela,et al.  Which are the wastes of construction , 2013 .

[11]  Bo Terje Kalsaas.  WORK-TIME WASTE IN CONSTRUCTION , 2010 .

[12]  Vicente González,et al.  A Production Model for Construction: A Theoretical Framework , 2015 .

[13]  Lauri Koskela,et al.  The Wastes of Production in Construction – a TFV Based Taxonomy , 2014 .

[14]  Patricia D. Galloway,et al.  Survey of the Construction Industry Relative to the Use of CPM Scheduling for Construction Projects , 2006 .

[15]  Russell Kenley.  The predictive ability of Bromilow's timecost model: a comment , 2001 .

[16]  Glenn Ballard,et al.  The Combination of Last Planner System and Location-Based Management System , 2010 .

[17]  Russell Kenley,et al.  Project Micro-Management: Practical Site Planning and Management of Work Flow , 2004 .