Global and Local Risk Factors Causing Correlation between Activities in Fuzzy Linear Schedules

Construction projects encounter numerous risk factors during their life cycle. Some risk factors can impede the progress of all or some activities and cause their durations to be correlated, which ultimately affects the entire schedule. This is especially visible in linear and repetitive schedules that plot the detailed work progress over time. This paper explores such risk factors that cause correlated activities and investigates their influences on fuzzy linear schedules. The contribution is twofold: First, it categorizes risk factors into global and local according to whether their effect is upon all activities within the schedule or not. It creates a mathematical model to simulate such risk factors on fuzzy linear schedules to evaluate and visualize their effects on project durations. Second, it investigates the promote-or-inhibit effect based on the correlation values that they can cause (where 0 to +1 promotes and-1 to 0 inhibits) within various schedules. This research enables decision-makers to evaluate risk factors to protect schedules by taking preventive action.