A Dynamic Job Shop Model for Scheduling Tasks in a Software Development Environment

Abstract

This work proposes a Dynamic Job Shop Scheduling (DJSS) model for scheduling the task in a softwareproduction environment. The aim is to organize the insertion of tasks in the shop in a precedence orderpreviously defined that obeys the mapping of the critical path and the critical chain to identify constraintsin the productive process. The complexity and dynamism of the software development environmentrequire a mature and adjusted process that enables management throughout its extension. Therefore, theUnified Process (UP) was used in conjunction with the Theory of Constraints (TOC) in the SoftwareDevelopment Process (SDP). The UP requires an efficient model for the processing of activities, givenby the set of independent variables involved in the process. For this reason, a model to programmingthe task based on dynamic scheduling was developed. The problem around the DJSS is to programthe tasks in the shop in a way that allows identifying one or more production lines in the shop withconstraints of capacity at runtime. A capacity constraint is any element that disturbs the productiveprocess, causing L={Mi Aj} to have delivery (DA) of less than 100% of the artifacts, given by the setof jobs (jn) scheduled. The resource with capacity constraint limits the production of the machines in theproduction line, leading to bottlenecks in the production process. A bottleneck, in turn, is denoted bythe production limitation of a machine (people) caused by one or more capacity constraints that implymaximum production, which in this case is defined by D={Mi, Aj=100%}. In this work, the maximumproduction is given by the set of tasks processed in each of the phases of the UP and according to theproductive calendar, which delimits the deadline of each delivery and establishes the budget of hoursfor the shop. The set of tasks scheduled and “rescheduling” and properly processed in all phases definethe total production of each machine. The use of DJSS facilitated the organization and management ofinsertion and rescheduling operations in the shop and as result, produced data to measure the effort/timethat allowed identifying the bottleneck of the software production process