Offsetting Line Station Orders

An assembly order consists of several LSOs. These LSOs are linked to line stations that are grouped in line segments. These orders and segments all have their own start times and end times. These times are calculated on the following occasions:

  • An assembly order is offset when you plan the order, that is, when LAC creates the assembly order in ASC.
  • A line segment is offset when you confirm a line sequence in the Simulate and Create Line Sequences (tiasl4200m000) session.
  • An LSO is offset in two instances:
    • When you plan the assembly order.
    • When you run the current session. This last instance is, of course, what we focus on now.

If you offset LSOs in the current session, the calculation depends on the status of the assembly orders. These statuses are:

  • Created. If you only planned an assembly order, and you did not yet confirm a line sequence, the assembly order has the Created status.
  • Sequenced. After you confirm a line sequence, the assembly order has the Sequenced status.

According to these statuses, offsetting is based on the following information:

  • For Created assembly orders, the calculation is based on the lead-time of the line segments, as defined in the Line Segments (tiasl1540m000) session.
  • For Sequenced assembly orders, the calculation is based on the sequence, assembly line calendar, and the assembly assignments of the assembly line.

The previous information implies that the start times and end times of LSOs can vary, according to the offset method that is used. Therefore, an LSO can have start times and end times on one of the following three levels:

  • If the LSOs of a Created assembly order are not yet offset in the current session, they have the start times and end times of the assembly order. Of course these values are initial values that cannot be calculated in the current session.
  • If you offset LSOs for assembly orders with the Created status, these LSOs get the same start times and end times as the line segments. This is because the start times and end times of the LSOs are calculated, based on the lead-times of the line segments.
  • If you offset LSOs for assembly orders with the Sequenced status, these LSOs receive the start times and end times of the line stations.

To offset LSOs in the current session, you must specify a range, an Offline Date To, and the order type for which the LSOs must be offset. However, not all assembly orders that match these criteria are offset, but only those assembly orders that require offsetting. Assembly orders that require offsetting have the Offsetting Required check box selected. This check box is displayed in the following sessions:

  • For Created orders, in the Assembly Order (tiasc2100s000) session, on the General tab. If the Assembly Order Status is not Created, the Offsetting Required check box is not displayed.
  • For Sequenced orders, in the Line Segment - Line Sequence (tiasl4500m000) session.

Offsetting is required as soon as a change in the dates or times of an order occurs, or, in other words, as soon as the actual dates and times no longer match the planned dates and times. The Offsetting Required check box, therefore, is selected in the following instances:

  • When LAC generates the assembly order in ASC.
  • If you mix or manually move planned orders and, as a result, these orders receive another offline date/time.
  • If you offset the LSOs of a parent order and as a result, this order receives another offline date/time, the check box is selected for the child orders; because the child orders must be synchronized with the parent order. Note that offsetting the LSOs of a parent order does not result in new start times and end times for the LSOs of the child orders. The LSOs of the child orders must be offset themselves too.
  • If you confirm a line sequence, in the Simulate and Create Line Sequences (tiasl4200m000) session, or manually change a confirmed line sequence, the line segments receive new start times and end times. As a result, offsetting is required for the LSOs. If the order has child orders, the check box is selected for the child orders too; because the child orders must be synchronized with the parent order.

Note that in all these instances, it is necessary to offset the LSOs of the orders in question, using the current session. The error messages for offsetting can be viewed in the Assembly Messages (tiasc0501m000) session.

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