Time-Cost-Quality Tradeoff Modeling based on Resource Allocation
Decision Variables and Assumptions
Calculating Labor Cost and Activity Time
When labors are working together as a construction crew in a construction activity , their working duration is the time of the construction activity, which could be estimated by the construction quantities (QNT) and the actual productivity, overtime factors:
where duration (time) of construction activity
quantities of construction activity
actual
productivity in activity
;
overtime factors if accelerated construction speed is desired,
when overtime varies from 0 to 4 hours per day since standard working time is eight hours per day. DPK
means no overtime work assigned.
Labor cost in construction activity would be determined by standard daily cost and overtime work cost [18]. It is assumed that work overtime is paid in an hourly cost rate comparing with standard labor cost:
where labor cost in construction activity
standard labor cost per unit time (e.g., day) in construction activity
labor cost rate factors in activity
when overtime work is applicable, usually