Order Proposals

Introduction

The Order Proposal routine scans all the parts that fulfill the selection criteria, in order to find the parts for which additional supply must be created.

A report is generated, and optionally, purchase requisitions, purchase orders, distribution orders, or shop order requisitions are created. You can also delete existing purchase requisitions and un-released distribution orders, provided they are created by order proposal.

This document describes the scanning logic in detail. It includes the following sections:
Criteria Affecting the Order Proposal - This section describes all the part settings that are used by Order Proposal.
Manufactured/Acquired Split and Order Proposal - This section describes how the order proposal is affected by the Manufactured/Acquired Split functionality.
Supplier Split and Order Proposal - This section describes how the order proposal is affected by the Supplier Split functionality.
Terms Used in the Calculations - This section defines all the terms used in the calculations.

Criteria Affecting the Order Proposal

The parts have to fulfill the criteria specified in the Create Order Proposal dialog box, as well as the following criteria:

Manufactured/Acquired Split and Order Proposal

When the order proposal has suggested the required quantity it is either manufactured or purchased depending on the part type. Before the quantity is sent to either manufacturing or purchasing, it could be split in accordance to the Manufactured/Acquired Split percentage as defined on the inventory part. If this split is used, one split quantity will be sent to manufacturing and the other split quantity will be sent to purchasing. Both split quantities should have been rounded using Scrap Rounding. When the order proposal is used the manufactured quantity is always put on a shop order requisition regardless of the default supply type or the manufactured supply type. The purchased quantity is put on a purchase requisition, purchase order, or distribution order as explained above, regardless of whether or not the purchase quantity is derived from a split.

Supplier Split and Order Proposal

Supplier split comes into use when the default supply type is Requisition. Then the order proposal passes along a quantity to the purchase requisition. The purchase requisition functionality considers the split for non-multi-site planned parts. This means that the only way to get the order proposal to consider supplier split is to use the supply type Requisition. Using this supply type implies that a distribution order will not be created, i.e. if the supplier split includes lines for multi-site planned parts, those lines will not be considered.

Terms Used in the Calculations

The following terms are used in the order proposal flowcharts:

Consider the following figures as an example when using Planning Method B;

Order point (OP): 25

Safety stock (SS): 10

Lot Size (LS): 8

Lead Time (LT): 21

The starting point for the order point calculation is to look at the current quantity and any old supplies and demands that should have occurred up until today. This is the projected value shown on the Inventory Part Availability Planning window.

Some practical figures of Inventory Part Availability Planning would be as follows;

Inventory Part Availability Planning:

Due Date

Type

Status

Supply

Demand

Reserved

Pegged

Shortage

Projected

Plannable

16.12.20XX

Cust Order

Partially Delivered

0

1

0

0

1

-1

 

22.12.20XX

Purch Order

Confirmed

14

0

0

0

0

13

 

25.12.20XX

Cust Order

Released

0

1

0

0

0

12

 

25.12.20XX

Cust Order

Released

0

1

0

0

0

11

 

25.12.20XX

Cust Order

Released

0

2

0

0

0

9

 

25.12.20XX

Cust Order

Released

0

2

0

0

2

7

 

29.12.20XX

Cust Order

Released

0

1

0

0

1

6

 

01.01.20XY

Cust Order

Released

0

2

0

0

2

4

 

05.01.20XY

Cust Order

Released

0

3

0

0

3

1

 

05.01.20XY

Cust Order

Released

0

2

0

0

2

-1

 

07.01.20XY

Cust Order

Released

0

1

0

0

1

-2

 

07.01.20XY

Cust Order

Released

0

1

0

0

1

-3

 

07.01.20XY

Cust Order

Released

0

1

0

0

1

-4

 

25.01.20XY

Purch Order

Released

24

0

0

0

0

20

20

10.03.20XY

Cust Order

Released

0

10

0

0

0

10

9999999,99

Purchasing Lead Time: 21

Unlimited Supply Date: 30.01.20XY

The projected quantity on-hand by 08-01-20XY then defines the starting point for the order proposal calculations for this part it is (-4). From this starting point, the order proposal will (as it is below OP at the starting point) look ahead one lead time (till the 29th of January) to see if there are any supplies planned for delivery during that time that takes the projected quantity on-hand above the OP.

Note that order proposal will only consider planned supplies when looking ahead for one lead-time of the part (i.e., it will not look at future demands unless they are abnormally high, see note below) If there were planned supplies that make the projected quantity on-hand become equal to or greater than the OP, there would not be any new requisitions added for this part.

For the above example the projected quantity on-hand (only considering future supplies) one lead time into the future is 20 (29.1. 20XY). This is due to the planned supply of 24 pcs that is due on 25.1.20XY. This means that we are still below order point when looking one lead time into the future (20):

Due Date

Type

Status

Supply

Demand

Reserved

Pegged

Shortage

Projected

Plannable

16.12.20XX

Cust Order

Partially Delivered

0

1

0

0

1

-1

 

22.12.20XX

Purch Order

Confirmed

14

0

0

0

0

13

 

25.12.20XX

Cust Order

Released

0

1

0

0

0

12

 

25.12.20XX

Cust Order

Released

0

1

0

0

0

11

 

25.12.20XX

Cust Order

Released

0

2

0

0

0

9

 

25.12.20XX

Cust Order

Released

0

2

0

0

2

7

 

29.12.20XX

Cust Order

Released

0

1

0

0

1

6

 

01.01.20XY

Cust Order

Released

0

2

0

0

2

4

 

05.01.20XY

Cust Order

Released

0

3

0

0

3

1

 

05.01.20XY

Cust Order

Released

0

2

0

0

2

-1

 

07.01.20XY

Cust Order

Released

0

1

0

0

1

-2

 

07.01.20XY

Cust Order

Released

0

1

0

0

1

-3

 

07.01.20XY

Cust Order

Released

0

1

0

0

1

-4

 

25.01.20XY

Purch Order

Released

24

0

0

0

0

20

20

29.01.20XY

Purch req

Planned

8

0

0

0

0

28

28

10.03.20XY

Cust Order

Released

0

10

0

0

0

18

9999999,99

Note that in the above picture a new purchase order (PO) requisition is added by the order proposal calculation for a quantity of 8 (the lot size), due on 29th of January (one lead time away if order is placed today). The projected quantity on-hand of 28 is now above the order point when looking one lead time into the future from today (i.e., the system date which is 08-01-20XY as per the the example given).

If we are to present this scenario in a more schematic way, then it would be as follows;

Before running order proposal:

x-axis    -    Time in days
y-axis    -    Quantity

A        -    Safety Stock
B        -    Order Point
a         -    Today
ab       -    Lead Time
a+ab    -    Today+ Lead Time

As can be seen, when looking one lead-time ahead into the future (the timeframe when new supplies would be received) the projected on-hand is below the order point. This means that a new supply should be added and it will be added as one lot size (or a multiple of lot sizes if required to take the level above OP). Once again, note that future planned demands are not considered, only planned supplies, except in situations of abnormal demand (see below). The reason that future demands are not considered is that the parameters of SS and OP should be chosen to cover the normal demands during lead-time. If future demands were to be considered, it would result in ordering too soon and a quantity-in-stock higher than required. Therefore, in simple terms, the order proposal could be said to be looking for;

(projected quantity on-hand + any planned supplies during the timeframe of one lead-time into the future).

Continuing with the example, after running order proposal, the projected quantity-on-hand would end up as shown below;

x-axis    -    Time in days
y-axis    -    Quantity

A        -    Safety Stock
B        -    Order Point
a         -   Today
ab       -    Lead Time
a+ab    -   Today+ Lead Time

Now, when looking one lead-time into the future, the projected quantity on-hand is above the OP and there is no need to add new requisitions. Running order proposal once more would not make any difference. The added requisition should be transferred to a PO and sent to supplier. If there is a delay in doing this, there is a possibility of re-planning requisitions that have not been transferred to PO the next time the order proposal is executed. (Old requisitions that were created by the Order Proposal and not transferred to PO can be removed when running the order proposal. Then, new requisitions with new dates will be added).

Consider what would happen in the following which is based on the above example if we have a new Customer Order added today (08.01.20XX) for a qty of 1 that has not been delivered:

The following situation would be resulted when running the order proposal tomorrow (09.01) (or it could be Monday (12.1)...):

x-axis    -    Time in days
y-axis    -    Quantity

A        -    Safety Stock
B        -    Order Point
a         -   Today
ab       -    Lead Time
a+ab    -   Tomorrow+ Lead Time

The resulting changes are not so big. The projected curve has moved one day to the left and the projected quantity has also moved a step equivalent to 1 pc (as the customer order was added ”yesterday”).

As time passes the projected curve will move to the left and downwards as new demands are created.

Over time there will be new requisitions added and if assuming a relatively smooth demand curve, the order size of these requisitions will be one lot size. The planning parameters for the part will mean that there will be new requisitions added approximately two times during a lead-time (as the lot size corresponds to just a little bit more than half of the demand during lead-time). This will give the following curve of actual quantity on-hand for this part:

x-axis    -    Time in days
y-axis    -    Quantity

A        -    Safety Stock
B        -    Order Point
a         -   Lead Time

Note that this represents a historical curve of the quantity on-hand for the part, as opposed to the previous charts that show current situation today and a projection of incoming supplies.

The actual quantity on-hand for this part should vary between safety stock and up till one lot size above that.

Note: The special logic described below is used when extremely high future demands have been entered.

If the future demand is higher than Order Point minus Safety Stock (OP-SS), the OP will be temporarily increased within the order proposal logic.

Note, the label A above should be placed where it belongs, i.e. where the safety stock is above a where the blue and red line starts.


x-axis    -    Time in days
y-axis    -    Quantity

A        -    Safety Stock
B        -    Order Point
a         -   Today
ab       -    Lead Time
a+ab    -   Today+ Lead Time
p         -    Demand from planned orders exceed expected demand a seen from (order point - safety stock).

For example, OP is 25 and SS 10, the expected demand during the lead time is 15. If a demand is entered that exceeds 15, e.g. 20, the system will temporarily increase the OP with the difference 20-15 = 5 and consider it as 30. Then the (projected quantity on-hand + any planned supplies during the timeframe of one lead-time into the future) is compared with the OP 30 to determine if any new supply should be created and at what order quantity.
The temporary changes of order point will not have any impact on the order point specified on the inventory part; it is only used in the order proposal.

Planning Method C

When using Planning Method C, the only difference is how the system calculates the quantity that is needed to order when the projected quantity on-hand is below the order point one lead-time ahead. Instead of ordering in multiples of lot size, method C orders up to the lot size. The system will check the total demand quantity for one lead-time to see if it is greater than the difference between the order point and safety stock. If so, the OP is temporarily increased. The system will take the greatest value of the temporarily increased OP and lot size to determine the order quantity.