Originally posted by: SatishKumarA

Hi All,

I am using cumulative function for a resource to calculate its usage. My resource can process more than one task (say two) in parallel.

cumulFunction ResourceUsage[m in TaskList] = sum(t1 in ResourceTaskListb:m==t1.Task) pulse(op_task[t1], 1);

forall(r in ResourceList)
ResourceUsage[r] <= ResourceCapacity[r];

The above representation of upper limit on usage is standard.

New Constraint: My resource cannot process one task at any point time when its capacity is two. that means, resource can process either two tasks or zero tasks(idle case).

I kept a statefunction for two tasks to be processed in parallel. And I tried the following for this requirement,

forall(r in ResourceList)
ResourceUsage[r] == ResourceCapacity[r] || ResourceUsage[r] == 0;

which is throwing an error. How to handle this in OPL?

Originally posted by: PhilippeLaborie

I would just add a constraint on each interval variable on the resource stating that the level of the resource should be 2 during the interval variable:

forall(r in ResourceList) {

  forall(t1 ...) { // t1 on resource r

    alwaysIn(ResourceUsage[r],op_task[t1],2,2);

  }

}

Originally posted by: SatishKumarA

Hi Philippe,

Thanks for the solution. It works.

I am thinking about the OR case(i.e, zero or two). I missed the point that, only when the interval is present, this constraint will be enabled.

Thanks,

Satish