I'm dealing with the problem and I am looking for some help. I thoroughly studied the documentation and tried several different approaches myself but can't seem to get it working the way i want it to work. Let me start by describing the problem: Observation has a duration which is a multiplication of 5 (minutes), besides this it has one or more required disciplines (explained later). ScheduleBlockPeriod is a period of 5 minutes which is connected to a scheduleBlock ScheduleBlock contains a list of disciplines which can be performed in this block (there can be 1..* scheduleBlocks) Explanation: An observation has to be planned into one or more scheduleBlockPeriod(s) since a observations duration can be bigger then a scheduleBlockPeriods period. I checked out the VRP application and based my model on that. The reason why scheduleBlockPeriod is chained has to do with the amount of periods there are. I will write a custom move at some point which limits the nextScheduleBlockperiod to only select a period which is from the same ScheduleBlock and is right after the current one. Below I added a classdiagram how i would want it to work: <http://drools.46999.n3.nabble.com/file/n4029842/planning_class_diagram_2.... After I run a construction heuristic on the program implemented as described in the classdiagram it tells me the solution is uninitialized, which is obvious because it assigns 1 scheduleBlockPeriod to the Observation. Because the duration of the observation is 5 minutes(the same as the duration of a scheduleBlockPeriod). This makes the chained variable nextScheduleBlockPeriod null, which it should be since it is 1 scheduleBlockPeriod "long". So basically im wondering if there is some sort of work around for this or perhaps someone is able to tell me that I am totally modelling it the wrong way. -- View this message in context: http://drools.46999.n3.nabble.com/After-numerous-of-different-approaches-... Sent from the Drools: User forum mailing list archive at Nabble.com.