The following code creates the resources, creates the activities, posts the precedence constraints, posts the resource constraints, and constrains makespan to be at least the end time of the last activity of each job.

We'll give a name to each activity. The format of this name is JiSjRr, to express the idea that the activity corresponding to the jth step of the ith job uses resource r.

  /* CREATE THE RESOURCES. */
  IloSchedulerEnv schedEnv(env);
  schedEnv.getResourceParam().setCapacityEnforcement(IloMediumHigh);
 
  IloInt j;
  IloUnaryResource *resources = 
    new IloUnaryResource[numberOfResources];
  char buffer[128];
  for (j = 0; j < numberOfResources; j++) {
    sprintf(buffer, "R%ld", j); 
    resources[j] = IloUnaryResource(env, buffer);
  }
  /* CREATE THE ACTIVITIES. */
  k = 0;
  IloInt i;
  jobs = IloAnyArray(env, numberOfJobs);
  for (i = 0; i < numberOfJobs; i++) {
    IlcInt j = i*numberOfResources;
    Job* job = new (env) Job(env, i, numberOfResources,
                             &durations[j], 
                             &resourceNumbers[j],
                             resources);
    job->addToModel(model, makespan);
    jobs[i] = job;
  }