anchor.diff:  . *Choose the model in which the number of planning entities is fixed during planning*. For example, in the Employee Rostering starter application, it is impossible to know in advance how many shifts each employee will have before Optaplanner solves the model and the results can differ for each solution found.
   On the other hand, the number of employees per shift is known in advance,
   so it is better to make the `Shift` relationship a problem property
  -and the `Employee` relationship a planning variable.
  +and the `Employee` relationship a planning variable as shown in the following examples.
   +
   image::DesignPatterns/employeeShiftRosteringModelingGuideB.png[align="center"]
   
  -// Not clear just what this diagram is showing:
  +In the following diagram, each row is a different example and shows the relationship in that example's data model. For the *N Queens* example, the Queen entity has a Row planning variable, which stores objects of type `row`. Many Queens may point to one Row.
   
   image::DesignPatterns/entityVariableAndValueExamples.png[align="center"]
   
   [NOTE]
   ====
  -Vehicle routing is an exception because it uses a <<chainedPlanningVariable,chained planning variable>>.
  -====
  -
  +Vehicle routing is different because it uses a <<chainedPlanningVariable,chained planning variable>>.
  +====
   
   [[assigningTimeToPlanningEntities]]
   == Assigning Time to Planning Entities
  
positive.code: [[designPatternsIntroduction]]
  == Design patterns introduction
  
  The design patterns in this section list and solve common design challenges.
  //Need to explain what design patterns are.
  
  [[domainModelingGuide]]
  == Domain modeling guidelines
  
negative.code: ====
  Optaplanner does not currently support a `@PlanningVariable` annotation on a collection.
  ====
  
  +
  For example, in the Employee Rostering starter applicaion the `ShiftAssignment` class is the many-to-many relationship between `Shift` and `Employee`.
  `Shift` contains every shift time that needs to be filled with an employee.
  