| Assembly assignment |  |
| An assembly assignment (defined in Line Assembly Control (LAC)) is the equivalent of the line level assignment in LAC. The purpose of an assembly assignment is to balance the resources over the line stations in a manner that optimizes line performance. For this reason, assembly assignments are also called line balances. The process engineer defines the period and range for an assembly assignment, and links process characteristics to the assembly assignment. Assignments are used to define process characteristics such as cycle time, man occupation, and machine occupation. Assignments are date-sensitive, so different process charactersitics can be applied to the assembly line over different periods (dates) and time ranges (times of day) on the same day. Process characteristics Several process characteristics can be defined by means of assignments. Process characteristics that are applicable to the entire assembly line are defined on the line level assignment (in LAC). Process characteristics applied at line station level are defined for other assignments, which are defined by line station and linked to the line level assignments. All process characteristics are applicable to a line level assignment, but are defined by several assignments. When the line level assignment is active, all assignments that are linked to it are effective. Assignments are defined for an assembly line. For each assignment, you specify the cycle time (average and nonaverage) and activity ranges (the period and time ranges for which the assignment is effective). In addition to cycle time, you can define the following process characteristics for an assignment: Man and machine occupation per station. These are the line station level assignments in LAC. Work team (operation per work team and work teams per station). This is the job assignment in LAC. Operations per station. This is the line station assignment in LAC. These process characteristics are linked to other assignments that are, in turn, linked to the assembly assignment. When an assembly assignment is valid, the assignments that are linked to it are also in effect. Average and nonaverage assignments There are two types of assignments, both of which exist at the same time: Average assignments Use an average cycle time (which you specify) based on the cycle times of the nonaverage assignments for the day. LAC uses the average assignment in planning. Planning in LAC is based on cycle time, calendar, and availibility type. An average assignment is valid for a day. Nonaverage assignments Use time-based cycle times that are applicable to the operations performed on the line. The cycle time can vary according to the time range that is provided for the assignment. A nonaverage assignment is based on specific times within a day. Note An average cycle time is not a mathematical average, but is a value that you consider to be a suitable average for the nonaverage cycle times over the course of a full day. Nonaverage assignments for a line must be defined for the entire day, even if no work is performed for part of the day. ERP LN takes the hours of the working day from the calendar. Nonaverage assignments are used to define order content. For generated (nonfrozen) orders, the order content is based on the first active, nonaverage assignment of the day. For frozen orders, the order content is based on the nonaverage assignment that is in effect at the time that the order is frozen. Nonaverage assignments are also used to offset the lead time during sequencing. When the order is sequenced, a lead time is calculated for every order. This lead time is based on the cycle times, and the applicable cycle time is retrieved from nonaverage assignments. |