Stochastic Analysis of Cyclic Construction Processes

Many construction processes are stochastic systems. A deterministic analysis of these systems may not allow for the random distribution of system events, resulting in poor or unrealistic system attributes. Two examples of such systems are the cyclic processes of earthmoving and concrete placing. While both processes have different objectives, their execution has much in common; in particular both can be modelled as queuing systems. Analysis of such models allows the construction engineer to firstly achieve improved estimates of the overall productivity and thus schedule operations better, and secondly, determine the effect of non-anticipated events such as excessive delivery or cycle times. Outlined are results obtained from studies of both earthmoving and concreting operations; both studies are based on data obtained from actual UK construction projects. Results have been encouraging and have been used by a major UK civil engineering contractor in the management of earthmoving operations. Preliminary results have indicated initially that a numerical model of earthmoving and concreting operations can be analysed using simulation techniques. Secondly, it has been shown that the estimation of construction operations using such techniques can be more accurate and realistic than when more traditional or deterministic methods are used.