How are positions taken into account ?

    Optiline supports two types of position (or ergonomic) constraints, workstation-level and operator-level positions. Each can be set in the Edit Position dialog to a defined value or be left unspecified, on both workstations and operations. Unspecified position constraints amount to "Any" position, in which case the optimization algorithm will select a value itself, so that the line be the most efficient.
    The positions are taken into account in assigning operations to workstations, and in scheduling the operations within multi-operator workstations. Below is a detailed explanation of how the various position constraints are taken into account.

    Workstation-level positions:

    General rule: all operations in a workstation, and the workstation itself, must agree on all the workstation-level position constraints. This means, for any of the workstation-level constraints:

  • On a workstation
    • A specified constraint forbids any operation with a different specified constraint to be assigned to the workstation. Operations with an unspecified ("Any") constraint are allowed
    • An unspecified constraint allows operations with any value of the constraint to be assigned to the workstation. However, all of them must agree: if an operation with a specified value X is assigned to the workstation, then all other operations must have X for that constraint, or have that constraint unspecified ("Any").
  • On an operation
    • A specified constraint forbids the operation to be assigned to a workstation with a specified constraint other that its own. It can be assigned to a workstation with the constraint unspecified, provided no operation with a different value for the constraint was previously assigned to that workstation
    • An unspecified constraint ("Any") allows the operation to be assigned to any workstation.

    Operator-level positions:

    General rule: an operator with a specified position can only perform operations done in that position, or with their position unspecified. Furthermore, within a workstation, no two operators can carry out two operations in the same position at the same time. This means:

  • In general, an operation can only be assigned to a workstation which operators are in positions compatible with the operation. In particular, for a multiple-operator operation
    • The parts of the task with specified operator position can only be carried out by operators in the same position, or operators with their position unspecified
    • The parts of the task with unspecified operator position can be carried out by any operator in the workstation, provided he or she is not busy with another operation at the same time.
    • So for instance, a three-operator operation with positions Left+Right+Any can be assigned to a workstation with three operators at positions Back+Any+Any, but cannot be assigned to a workstation with operators at positions Back+Front+Any.
  • On a workstation
    • An operator with a specified position can only carry out operations done in that same position, or operations with that position unspecified ("Any")
    • An operator with an unspecified ("Any") position can carry out operations with any value of that constraint. However, he or she cannot do so at the same time as another operator works in the same position.
    • Note that operators with both specified and unspecified position can be mixed within the same workstation with several operators. In that case
      • Operators with a specified position will only carry out operations with that same position, or with that position unspecified ("Any")
      • Operators with unspecified position will carry out any operation
      • However, no two operations with the same specified position will take place at the same time (this may induce delaying the operation until another task done in that position is finished).
  • On an operation
    • An operation with specified operator-level position cannot be carried out by an operator with another value for that constraint. It can be done by an operator with unspecified ("Any") position, provided no other operation with the same value of the constraint is being carried out at the same time (this may induce delaying the operation until another task done in that position, by any other operator, is finished).
    • An operation with an unspecified operator-level position ("Any") can be carried out by any operator in the workstation Furthermore, it can be carried out at the same time as any other operation, including operations with the constraint unspecified
    • Note that an operation requiring several operators can mix both specified and unspecified operator positions for its operators. In that case
      • The part of the work with specified operator position will only be assigned to workstation operators in that same position, or to operators with that position unspecified. In any case, that task will not be carried out at the same time as any other task with the same specified position, whatever the operator
      • The part of the work with unspecified operator position will be assigned to any operator, possibly at the same time as any other operation.