IBM ILOG Scheduler User's Manual > Integrated Applications > Writing Multi-Threaded Applications Using Durable Resources > Designing a Model

As in Chapter 22, the workers are modeled as unary durable resources with breaklists and with the corresponding timetable constraints added. The fact that there are now several operators simultaneously handling requests translates into running several threads, each one corresponding to an operator and each one disposing of its own environment (object of type IloEnv) and of its own solver (object of type IloSolver). These threads are created by constructing an object of type IlcWorkServer. This object allows you to dispatch the requests among threads transparently.