| # Printing Production Order Planning by Priority You can select in the Print Priority field which criterion LN uses to decide which orders have the highest priority. You can select one of the following criterions: Critical Ratio Earliest Due Date Priority of Prdn Order Shortest Total Rem.Prd.Tm Slack Time If you manually enter a production-order priority in the Production Orders (tisfc0501m000) session, you can express the priority in a number in the range 0-999. The default is 999. This number expresses the lowest order priority. The highest priority in LN is 0 (zero). The report includes the following data: Priority Production order Operation Project Item Machine Task Work center Note If the report takes a long time to be produced, it may help to limit the range of orders (and other variables) that you select. Days Late The Days Late column is one of the columns printed in the report. The Days Late is calculated as the difference (in days) between the production order's Planned Delivery Date and the Reference Date as defined in the Print Production Order Planning by Priority (tisfc1410m000) session. Each day on which working hours are available is counted as one day late. For the first day and the last day, working hours are exactly calculated to determine the days late. Note Maximize your window, if necessary, to view the following diagrams correctly. Example Value of the Reference Date field: 26 August 1998. This is the date on which the calculation of Critical Ratio and Slack Time as priorities is based. A production order A1 consists of 4 operations:
operation | start date | end date | slack | overlap*
--- | --- | --- | --- | ---
10 | 25-Aug-98 | 2-Sep-98 | 0 | 50 %
20 | 29-Aug-98 | 15-Sep-98 | 0 | 0 %
30 | 15-Sep-98 | 10-Oct-98 | 8.0 | 0 %
40 | 18-Oct-98 | 30-Oct-98 | 0 | 0 %
*The overlap percentage is based on the transfer batch quantity. The time-frame diagram: 4 methods exist to calculate the Critical Ratio and the Slack Time, dependent on whether the Production Time Including Overlap Time check box is selected: Method 1: without overlap or slack time between operations Method 2: with overlap, without slack time Method 3: without overlap, with slack time Method 4: with overlap and slack time Critical Ratio
| Operation time |
Method | 10 | 20 | 30 | 40 | A* | B* | C* | D*
--- | --- | --- | --- | --- | --- | --- | --- | ---
- overlap -slack | 8 | 17 | 25 | 12 | 62 | 66 | 1.06 | 4
+overlap -slack | 4 | 17 | 25 | 12 | 58 | 66 | 1.14 | 8
- overlap +slack | 8 | 17 | 33 | 12 | 70 | 66 | 0.94 | -4
+ overlap +slack | 4 | 17 | 33 | 12 | 66 | 66 | 1.00 | 0
*
A | Remaining production time
B | Planned Delivery Date - Reference Date
C | Critical Ratio
D | Slack
Using Method 3:
    Critical ratio (CR) = 66 / 70 = 0.94
If the Critical Ratio = 1, the order is on schedule > 1, the order is ahead of schedule < 1, the order is behind schedule. Slack Time
     Slack time=(Planned Delivery Date-Reference Date)-remaining production time
Using Method 3: Slack time = 66 - 70 = -4 If the Slack Time = 0, the order is on schedule > 0, the order is ahead of schedule < 0, the order is behind schedule |