Scheduling - Constrain an Operation to start and finish within 1 working day?

Hi all,

I’ve been lurking for a while, but this is my first post. I couldn’t find any posts in my searches that addressed this.

We are working in a test environment to get MRP and Global Scheduling working for us (long story short, LOT’s of poor-setup ghosts to exorcise from the last 8 years!). We have made great progress (details below), but we have run into an obstacle I have yet to find my way around.

One of our plants manufactures about 340 unique parts, each of which have 2 operations. We have the resource groups set up, and resources and operations built out in MoM for the parts, along with production calendars marking non-working days and work hours. For the most part, the schedule and unfirm job suggestions are making sense (respecting finite limits, total production time make sense, operations logical with respect to the job).

The issue is that the first operation MUST, practically speaking, start and finish within the working hours of 1 work day (we make precast concrete products - so once the concrete mix(es) are ordered for the ‘wet-side’ pouring operation, the entire operation needs to be completed that same day). The MRP/Scheduling engines are respecting our working hours and days, but often this operation will be scheduled to start on one day and finish on the next - and I can’t figure out how to (or if I can?) define that as a constraint.

Our jobs call for production times on the first Op anywhere from 30 minutes to the full 18 hours - but I would love for the scheduling engine and job suggestions to ensure any job starts and finishes within a single working day, and build the schedule out around that constraint.

I’d appreciate any thoughts you may have!

Current setup details:

  • Epicor 10.2.700
  • Do NOT have Advanced planning & scheduling module
  • Running MRP and Global Scheduling (backward Scheduling)
  • Finite Scheduling with a horizon of 180 days
  • Parts are setup with MoM including Ops, Resources, production standard minutes/piece, etc.
  • Production calendar set and assigned to resources (18 working hours / day)

Let me know if you need any other information about our setup. Thanks in advance.

To start, I would make the resource that has to complete the operation in one day infinite. If you can’t get the items to schedule in one day in that environment, you’ll never get them to schedule that way finitely.

1 Like

Thanks for the reply, Gil.

Just to make sure I’m following your logic correctly; would that just be a temporary test to rule out other issues causing the job to schedule beyond 1 working day? Would infinite scheduling on that resource line those ops up at the start of the day? Or is it just easier to play with other variables in infinite?

If I’m totally out to lunch and missing your point, please let me know :slight_smile:.

For more context:
We have 2 Resource Groups set up for this plant.

  1. Stb Hess Molds
  • this has 75 Resources - 1 for each mold we have
  • All are Finite Capacity
  • 180 Finite Horizon
  • 5day 18hour production calendar
  • 24 Hour Move time (to allow for curing between op10 and op20)
  1. Stb Hess Production
  • this has 2 Resources;
    – the ‘wetside’ automated machine that mixes and stamps the concrete (24 hour move time)
    – the ‘dryside’ which palletizes the cured concrete (no queue or move time)
  • All are Finite Capacity
  • 180 day Finite Horizon
  • 5day 18hour production calendar

These parts typically have 2 Ops in their BOO:

Opr: 10 OP: SHessWet


  • OpDtl: 10 - Specific Mold Resource is Selected from Stb Hess Molds Group
  • OpDtl: 20 - Stb Hess Wetside Resource is selected from Stb Hess Production Group

Opr: 20 OP: SHessDry


  • OpDtl: 10 - Stb Hess Dryside Resource is selected from Stb Hess Production Group

Would I make JUST the Hess Wetside Resource on Op 10 infinite? or both the Wetside and Mold resources infinite?

As well - if anything with our op / resource group / resource setup seems out of place, please let me know.

Thanks again,

For the resource with the 24 hour move dry time, I would assume that this can dry overnight on “off calendar” hours. Double check that you have the Use Calendar for Move Time checkbox off.

Is there set number of molds that can be run in a given day? Because that is one scenario the Advanced Scheduling module can handle. For instance no matter what the mold part is you can only do 100 per day with one machine.

That is correct, the drying can happen overnight. I double checked just to be sure, and the Use Calendar for Move Time checkbox is indeed unselected. Based on what we’re seeing in the resource scheduling board, this makes sense as well (Operations are scheduled based on the calendar production hours, and the move time is a fixed 24 hours regardless of production hours).

Everything is lining up really well in terms of timing between first and second ops (wetside op, move time to cure, then dryside palleting op), as well as scheduling efficiency within finite constraints on the resources themselves.

Regarding your scenario / question about limiting mold runs / day: It is rare that we would have demand for more than a day’s worth of parts on a single mold, even with days of supply set 30 days out (we can do 4050 mold presses in an 18 hour production day, if we are running a single mold without changeovers). On the few parts that have that level of demand, we are currently controlling that by setting max lot sizes at the part level to break up those jobs suggestions into 1 day maxes.

More typically, we are running 2-4 parts (with their corresponding molds) through their wetside operations on that resource per day - sometimes up to 8 for small special order runs.

Based on our observation, job / operation sizes are being suggested/scheduled as expected - none of the operations in the job suggestions currently require more total production hours than we have in a day (18) - the issue is that the start times of our operations in a given day does not reflect that it must complete by the end of that working day.


  • ProdCal Working hours are 6am - 12am (18 hours)
  • Estimated production hours for an op in a job suggestion is 6 hours
  • Scheduling places the start time for the op at 10pm, finish time next day at 10am.
  • It respects that the total op time must be within production hours (skips over 12am-6am ‘off time’) - I just can’t find a way to constrain the system so that the operation starts no later than 6pm (in this example - that time would be dynamic based on est. prod hours), so it completes by 12am (by end of working day).

Are there any options for this scenario in Advanced Planning?

I wonder if a “Daily Production Capacity” (Resource Group) combined with a “Production Consumption Rate” (MOM Operation) might apply?

@bordway - I’m intrigued, but can’t picture what that might look like practically. Are you able to provide a simple setup example?

I would take a look at the scheduling tech ref guide in the E10 Help.
Note that it requires the Advanced Planning & Scheduling module.
And I’m only going guessing… based on a demo I saw once using these, that I “kind of” remember being something like the case you describe.

FWIW, a couple screen shots from the tech ref guide.

Thanks much - I’ll dig into these. I’ve been getting really cozy with the technical reference guide lately, so this is a great fit :laughing:

Definitely looks promising from first read.

@bboes - Looking back, I’m wondering if this is maybe what you were referring to as well? If so, then my apologies for not understanding and running past.

Yes, that was my exact point. If you can’t fit the operation in the resource infinitely, then you can isolate the problem to simple math. If you are fighting for resources with other parts, you can’t even make that determination.