An Optimization Model for a New Scheduling Problem: Application in a Molecular Biology Lab

A new batch process scheduling problem is studied in this paper. The problem considers several machines where the jobs are processed and a team of specialists who analyze the jobs' results. Two operations that add complexity to the problem are the potential repetition of one or more processes and the probabilistic decision about the reprocessing of the jobs. A known State-Task Network partially represents the problem, so it is extended to include the two operations mentioned before and also the participation of a technical team. Based on this representation, an integer programming model is formulated for the integrated scheduling problem so that all the resources, material and human, are used in the best possible way. Actual data from a research lab located in the Region del Maule, Chile, illustrates the model's performance. The results showed that the scheduling obtained significantly contributed to planning the resources at the research lab. Changes in the technical team and instruments are possible so that the model could also be executed, only changing the corresponding parameters. Furthermore, additional experiments to the case study were conducted to study the performance of the model by increasing the size of the parameters.