Why didn't the engine find any results?

There are a number of possible reasons why the engine may not find any results for your caseload:

  • Your caseload has conflicting constraints
  • Your caseload has too many "hard" constraints
  • Your caseload is too large given your available therapy time

Rule of thumb: We're dealing with mathematics, not magic. The scheduling engine will do exactly what we've told it to do.

As a starting point, please be sure you've followed the steps in our best practice guide: How to quickly find your best schedule.

Conflicting Constraints

Here is an example of conflicting constraints:

  • A student's Exact Time set to Mon 2:00 PM
  • That same student's 'Must Not' availability set from Mon 1:00 PM to Mon 3:00 PM

You can think about this in terms of handing the scheduler a bunch of puzzle pieces, which don't (and can't) fit together.  In other words, the scheduler can only find a solution if the puzzle pieces you give it somehow fit together.

Here are some things you can try:

  • Generally, conflicting constraints are caused by mistakes while entering the caseload data.  Check back over your caseload configuration, and ensure that there are no conflicting pieces of information.

For help identifying what constraint might be causing the conflict:

  1. Look at the score of the top row in the table of Candidate Schedules (that's your best score)
  2. See what your best score means in the What do the Scores mean? article
  3. Adjust the item in your caseload that corresponds with the best score

Too Many "Hard" Constraints

Hard constraints generally slow down the scheduling engine. The particularly confusing thing about having too many hard constraints is that there may be viable schedules out there--but it's unlikely that the scheduler will find them within its computation window.

Sometimes it's possible to have made a schedule by-hand that the scheduling engine didn't find in its computation window. In that case, the scheduler would have eventually produced the schedule you made by hand (or a better one), but due to all of the hard constraints, it would have taken weeks or months (or longer!) to do so.

Your ideal schedule may be mathematically out of reach, but SLP Scheduler can still help you get the best possible schedule.

Here are some things you can try:

  • Convert some hard constraints into soft constraints.  Hard constraints vs. soft constraints
  • Loosen as much criteria as you can. For example, replace instances of "Must Not" availability entries with "Prefer Not". Don't worry ... the scheduling engine will still try to avoid as many of the "Prefer Not" slots as possible, only using them when necessary.
  • Reconsider any self-imposed constraints. Some of your constraints come from your state's laws, or from policies that your administration has put in place. If any of the constraints you've entered are really your own preferences, try removing them. The scheduler works best when the only hard constraints are the ones that are absolutely necessary.
  • Other examples of criteria that you can loosen can be found on the What do the Scores mean? article. Items in the table with a negative score can usually be relaxed one way or another.

If your hard constraints are truly non-negotiable, then there's a high likelihood that your caseload (with all of its current constraints) is mathematically unsolvable.  (This tends to be really good ammunition if you need to go back to your administration and ask that some of your constraints be relaxed.)

If your administration comes back with a "do the best you can", we can easily accommodate that. Simply change your hard constraints into soft constraints (see above), and the scheduler will do the best it can with all of your constraints. The resultant "best effort" schedule is essentially the best that can be done without removing students or sessions from your caseload.

Caseload Is Too Large

If you have an unusually large caseload, or relatively few days to see all of your students, the scheduling engine may not have enough available therapy time to squeeze everything in.

Here are some things you can try:

  • Increase the "Maximum Group Size" value for every therapist in your caseload to the legal maximum for your state
  • Increase the "Maximum Grade Span" value for every therapist in your caseload
  • Consider converting student sessions with an "Individual" delivery model to "Unspecified"
  • Reduce your "Minimum Scheduled Interval" value to 5 (or even 1)
  • Instead of scheduling students for multiple sessions per rotation (i.e. per week), schedule each student for only one session per rotation
  • Remove exact time spans from students in your caseload
  • Don't schedule your sessions in alignment with class periods
  • Reduce the "Days Apart" value for every student in your caseload to 0 or 1
  • Un-check the "Locked to Building" checkboxes for every therapist in your caseload
  • Remove any non-critical "Must Not" entries for every therapist in your caseload
  • Remove any non-critical "Must Not" entries for every student in your caseload, or convert them to "Prefer Not" entries
  • Add another day to your schedule (or increase your available hours)
  • Add another therapist to share your caseload
  • Reduce the number of students in your caseload

If these ideas aren't negotiable, then you may need to have a chat with your district about reducing the constraints or size of your caseload. If the engine can't find a solution, then there's a high likelihood that a solution respecting all constraints doesn't mathematically exist.

Manually Partition

If you have multiple therapists in your caseload, consider manually partitioning your single caseload into two separate caseloads--one caseload per therapist.  Then, each therapist could be scheduled separately--and more quickly.  More info.

If you'd like help partitioning, please contact Support.  We can easily duplicate your exact caseload (one for each therapist), which saves you the effort of having to manually reenter any data.  Simply remove the students handled by the other caseload, and click the big green "Schedule" button again on both caseloads.

Still Stuck?

If you still don't have any luck, please contact Support.

If you think you've outsmarted our scheduling engine, please check out our "(Wo)man vs. Machine" Challenge.

This article was helpful for 5 people. Is this article helpful for you?