[rules-users] [Drools Planner] Proof-of-Concept Stock-planning System

[Geoffrey De Smet]

Op 03-04-12 23:10, Reinis schreef:
> Hello,
>
> I want to ask you, guys, if you could guess if it is possible or
> probable to build such a System with Drools Planner:
>
> The system shall plan the best time where the transport unit (TU) has to
> be input into stock system to reach set delivery deadlines, utilization
> of resources and load balancing of bottle necks (all expressed as rules).
>
> Most of things (resource capacity, route within the stock system, etc.)
> are given and constant facts. Actually there is only one planning
> variable - time interval of a transport unit characterizing retention
> period within a given Resource. Like this:
>
> TU#1 is in Resource #A from 11:00 till 11:30<- the optimal interval has
> to be planned
Is the value range something like this:
(A)
- 10:00 till 10:30
- 10:30 till 11:00
- 11:00 till 11:30
- 11:30 till 12:00
Or like this?
(B)
- 11:00 till 11:15
- 11:01 till 11:16
- 11:02 till 11:17
- 11:03 till 11:18
...
 From reading further, I presume (A).

> TU#1 is in Resource #B from 11:45 till 12:00<- the optimal interval has
> to be planned
>
> TU#1 is in Resource #C from 12:30 till 13:00<- the optimal interval has
> to be planned
>
> I have following problem size and constraints:
> - TUs per day: 160'000
> - Amount of resources a TU travel through: 3
Do the TU need to go through it's 3 resources in a specific order?
(C) No
(D) Yes
I presume it can not go through 2 resources at the same time.
> - Average smallest time interval: 15 Min
> - Planning period: 09:00 - 16:00 = 8 hours = 32 intervals
> - Initial planning window: 4-6 hours
> - continuous planning multiple batch execution time during the day after
> addition and/or retraction of number of TUs: 20 minutes
(E) This is repeated planning (see documentation manual if you haven't 
already).
> So the problem size would be(?):
> (TUs * resources) ^ intervals = (160'000 * 3) ^ 32 = 6.305500958×10¹⁸¹
That's not a big search space. In some examples I 've seen 10^6800.
Of course, the search space isn't the only metric to take into account
(but I haven't found a good way to measure the other metrics,
such as how-constrained-is-the-problem, how-big-is-the-snowball-effect, 
...).
> I know there is no one answer to this question. I would like only to get
> your feeling on this problem. Would you take on solving this sort of
> problem with drools planner?
Definitely :)
If it's (A) and (C), it should be an easy, standard implementation.
If it's (B) and (D), then it becomes interesting :)

The only part I expect some rough edges is (E).
I suspect you'll be asking for build-in support for "planning entity 
locking" to do your continuous planning easily.
   https://issues.jboss.org/browse/JBRULES-3359
It's a PITA to do that yourself for now.
> thanks and br
> Reinis
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-- 
With kind regards,
Geoffrey De Smet