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

Method	10	20	30	40	A*	B*	C*	D*
	Operation time
- 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