Automation of the net working duration technique for analysis of construction delays and work changes

ABSTRACT Delays and work changes is the most common problem in the construction industry. Many methods have been developed for analysis of delays. In this research the net working duration based model is illustrated and automated with MS project using visual basic for applications (VBA) programming language. The automated model can deal with real life project networks by reducing the network into equivalent one with only paths affecting the analysis leading to less effort and cost for delay analysis. Viewpoints of float ownership and concurrency of delays are major factors affecting the delay analysis results. A percentage method which deals with multiple critical paths is used within the automated model instead of accounting for concurrency of delays. Also a suitable and flexible concept of total float ownership is used with the automated model. Delay analysis using the automated model requires MS project updated schedule, the baseline which represents project as-planned schedule, and liability of delays lying on the equivalent network only. A hypothetical example is used to illustrate the model and a practical case study is used to compare the model results with other methods. The automated model enables project participants to identify their responsibilities towards project delays and work changes precisely.