Integration of Lean Con. and Building Information Modelling
that consume resources but do not add any value and can be and must be removed from the production
system immediately.
Koskela divided waste into two main groups: waste due to human action and waste due to flow of
materials (Project management day in Tallinn, 2008). In the execution stage, waste caused by human
activities occurs in two common construction situations: work inactivity and ineffective work (Serpell,
Venturi and Contreras, 1995). Causes for work inactivity: travelling, idle work, resting, waiting time
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and physiological needs. Causes for ineffective work: rework, inventing working and working slowly.
Of course many of these causes are subjective, but to understand the time spent on value adding
activities, all activities must be considered.
annaabi.ee 
