TY  - CONF
TI  - The Investigation of Lead-Time Buffering Under Uncertainty Using Simulation and Cost Optimization
C1  - East Lansing, Michigan, USA
C3  - 15th Annual Conference of the International Group for Lean Construction
SP  - 580
EP  - 589
PY  - 2007
AU  - Srisuwanrat, Chachrist
AU  - Ioannou, Photios G.
AD  - Ph.D. Candidate, Civil and Env. Engineering. Department, 2350 G.G. Brown, University. of Michigan, Ann Arbor, MI 48109-2125, christ_cv@hotmail.com
AD  - Professor, Civil and Env. Engineering. Department, 2350 G.G. Brown, University of Michigan, Ann Arbor, MI 48109-2125, photios@umich.edu
ED  - Pasquire, C.L, Christine L.
ED  - Tzortzopoulos, Patricia 
AB  - The impact of uncertainty and variability in the productivity of trades aggravates the problem of work interruptions and idle time within repetitive activities. To eliminate the interruptions and idle time in order to achieve smooth work flow of resources, activities are deliberately delayed from their early start date. However, this practice induces a problem of tradeoffs between project cost and duration. Many recent studies have suggested that different types of buffers can be used to absorb the impact of uncertainty and variability on production work flow and most studies focus on using buffer to determine “when to halt an on-going production line”. In contrast, this paper focuses on “when to start a production line so that there is no interruption”. Two different approaches to lead-time buffering, the sequence step algorithm (SQS-AL) and the completed unit algorithm (CU-AL), are investigated using STROBOSCOPE (a discrete- event simulation system) with a special search add-in that implements a genetic-algorithm (GA). The investigation reveals that applying lead-time buffer provides better work flow and greater project profit; however, these depend on the penalty cost of work flow interruption and indirect cost. Both algorithms have implications that translate to advantages and limitations depending on assumptions, simplicity of simulation model, project characteristics, and uncertainty.
KW  - Lead-time buffering
KW  - the sequence step algorithm
KW  - the completed unit algorithm
KW  - production work flow
KW  - continuous resource utilization
KW  - idle time
KW  - simulation
KW  - STROBOSCOPE
KW  - genetic algorithm
KW  - profit maximization.
PB  - 
T2  - 15th Annual Conference of the International Group for Lean Construction
DA  - 2007/07/18
CY  - East Lansing, Michigan, USA
L1  - http://iglc.net/Papers/Details/533/pdf
L2  - http://iglc.net/Papers/Details/533
N1  - Export Date: 26 April 2024
DB  - IGLC.net
DP  - IGLC
LA  - English
ER  -