Design of a decision support system for the scheduling of a workflow process for a water utility company

摘要

The water utility in the District of Columbia is responsible for repair and maintenance of the water distribution system. The Distribution and Maintenance Branch (DMB) closes an average of 1431 maintenance work orders each year. Despite this closure rate, in January 2017, there was a backlog of 320 unclosed work orders open for more than 90 days. To reduce the backlog and maintain it at a steady state of approximately ten work orders, there is a need for DC Water to refine and implement an improved work flow. Based on the work order schedule analysis the following scheduling enhancements were identified: 1. Scheduling to minimize travel time between work orders. 2. Dedicating one repair crews to only low priority work orders. A stochastic petri-net simulation was developed to model the work flow process and the proposed design alternatives. The results of the simulation for the proposed alternatives were: Scheduling a dedicated repair crew for the low-priority had a 5.2% improvement in terms of time in system, 160% improvement in terms of backlog size, and 31% improvement in terms of closed work orders. For the travel time design alternative results showed that there was a 4.8% improvement in terms of time in system, 6.2% improvement in terms of backlog, and 2.8% improvement in terms of closed work orders. The utility analysis identified the dedicated repair crew option as the best alternative. Based on these results, DC Water is running a pilot test.