Baan Provides very good MRP logic, here is a Baan help document on how MRP in Baan IV works
Standaard_data Generate Planned MRP Orders (timrp00020sf0010) Company : 000
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When generating planned MRP orders via the session “Generate Planned
(MPS)/MRP Orders/Batches (timrp1210m000)”, the following actions are
carried out:
1. Delete planned MRP orders
2. Read in requirements
3. MRP orders for RPT-oriented MRP items
4. MRP orders for non-RPT-oriented MRP items
5. Generate rescheduling messages
1. DELETE PLANNED MRP ORDERS *
First all existing planned MRP orders with the order status
“Planned” will be deleted by the system.
2. READ IN REQUIREMENTS *
Planned MRP production orders and planned MRP purchase orders are
generated on the basis of the requirement per date. This
requirement may originate from the following:
– Current purchase orders and purchase contracts from the module
“Purchase Control (PUR)”.
– Sales orders and sales contracts from the module “Sales Control
(SLS)”.
– Replenishment orders from the module “Replenishment Order Control
(RPL)”.
– Service orders from BAAN Service
– Production orders for MPS items and MRP items which have been
planned and not yet reported completed. The planned order
delivery date is determined with the aid of the production
planning. A scheduled receipt is recorded on the computed
delivery date, in which case account is taken of any
subdeliveries that have already taken place.
– Allocations of materials for production orders are read from the
actual data and recorded as scheduled issues per item. In the
module “BOM Control (BOM)” materials have been assigned to an
operation.
The issue date is the planned start date of the operation in
question, in which account is taken of previously issued
materials and subsequential deliveries.
– All planned material requirements of projects that have the
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Standaard_data Generate Planned MRP Orders (timrp00020sf0010) Company : 000
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status “Active”. Their calculation must be carried
out in advance via the session “Generate Planned PRP Orders
(tipcs5201m000)”.
– The rough requirement for critical materials of MPS items.
– The sales quotations from the SLS module which have been selected
for the MRP calculation.
– The MPS orders which are planned, confirmed and firm-planned.
– The MRP orders which are firm-planned and confirmed.
– The sales forecast for MRP items.
3. MRP ORDERS FOR RPT-ORIENTED MRP ITEMS *
When generating planned MRP production orders, a distinction must
be made between RPT-oriented MRP items and non-RPT-oriented MRP
items.
When generating planned MRP production orders for RPT-oriented MRP
items, account is taken of the following order parameters from the
session “Maintain Item Data (tiitm0101m000)”:
– MPS/MRP Order System RPT Items, to determine the operation route and
the order quantity;
– RPT Item Order Per., to generate day or shift orders for the
relevant MRP item;
– Min. Remaining Percentage, to determine whether the system must
generate a new planned MRP production order or increase the order
quantity for the last generated and planned MRP production order;
– Minimum Order Quantity, to determine the minimum order quantity;
– Safety Time, to determine the planned delivery date for the
planned MRP order (based on the company calendar created in the
session “Maintain Company Calendar (tirou4101m000)”);
– Order Lead Time, to determine the planned start date for the
planned MRP order on the basis of the company calendar (unless
an (order quantity-dependent) operation has been defined for the
MRP item in question).
When generating planned MRP production orders for RPT-oriented MRP
items, account is taken of the available working time recorded for
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Standaard_data Generate Planned MRP Orders (timrp00020sf0010) Company : 000
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the relevant bottleneck work center in the session
“Maintain Company Calendar (tirou4101m000)”.
Next, the RPT schedule is updated. The following order parameters
from the session “Maintain Item Data (tiitm0101m000)” are then checked,
in which case exceptions are reported by the system:
– Minimum Order Quantity
– First Allowed Order Date
4. MRP ORDERS FOR NON-RPT-ORIENTED MRP ITEMS *
When generating planned MRP production orders for non-RPT-oriented
MRP items and when generating planned MRP purchase orders, account
is taken of the following order parameters from the session
“Maintain Item Data (tiitm0101m000)”:
– Order Interval, to determine the total requirement during the
order interval.
– Order Method, to determine the order quantity;
– Economic Order Quantity, if the order method is “Economic Order
Quantity”;
– Fixed Order Quantity, if the order method is “Fixed Order Quantity”;
– Minimum Order Quantity, to determine the minimum order quantity;
– Maximum Order Quantity, to determine the maximum order quantity;
– Order Quantity Multiple of, to round off the order quantity. If the
MRP item is a manufactured or generic item, the order quantity is
rounded to an integer;
– Safety Time, to determine the planned delivery date for the
planned MRP order (based on the company calendar defined in the
session “Maintain Company Calendar (tirou4101m000)”);
– Order Lead Time, to determine the planned order date for planned
MRP orders (for purchased items this calculation is based on five
working days per week, whereas for generic items the calculation
is based on the company calendar as defined in the session
“Maintain Company Calendar (tirou4101m000)”). Note: As to
manufactured parts the start date for the planned MRP order is
determined on the basis of the (possibly order quantity-dependent)
operation route and the work center calendar or the company calendar.
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Standaard_data Generate Planned MRP Orders (timrp00020sf0010) Company : 000
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When generating planned MRP production and purchase orders, account
is also taken of the field “Maximum Number of MRP Orders per Day” from
the session “Generate Planned (MPS)/MRP Orders/Batches
(timrp1210m000)”. If multiple MRP orders are generated per day, then
the relevant MRP orders are optimized in such a way that the total
order quantity is minimal.
After generating a planned MRP production order for a
non-RPT-oriented MRP item and after generating a planned MRP
purchase order, the following order parameters from the session
“Maintain Item Data (tiitm0101m000)” are checked, whereby exceptions
are reported by the system:
– Minimum Order Quantity
– Maximum Order Quantity
– Order Quantity Multiple of
– Fixed Order Quantity (if the MRP item’s order method is
“Fixed Order Quantity”)
– First Allowed Order Date
5. RESCHEDULING MESSAGES *
After the planned MRP orders have been generated for the relevant
MRP item, the necessary rescheduling messages are generated.
Account is then taken of the parameters “Display Item Foreground” and
“Display Process Info Foreground” from the session “Maintain MRP
Parameters (timrp0100m000)”. If the expected inventory level falls
below the lower margin or exceeds the upper margin of the planned
inventory level, rescheduling messages will be generated by the system,
if necessary.
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Standaard_data Calculate Demand Forecast by Item (tdinv4230m000) Company : 000
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SESSION OBJECTIVE
To calculate the demand forecast by item for the short term by item. The
system uses the demand forecast when calculating:
– the safety stock
– the reorder point
HOW TO USE THE SESSION
1) The safety stock:
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|S = K x 1.25 x MAD Sqrt ((Oint x 5/7 + Oltm + Sftm)/Period Length)|
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in which:
S = safety stock
K = safety factor determined by the system on the basis of the service
level
MAD = mean absolute deviation
Oint = order interval
Oltm = order lead time
Sftm = safety time
Period Length = (52 x 5)/number of periods
2) The reorder point
+———————————————————–+
| Dem.forec. x (Oltm + Oint x 5/7 + Sftm) |
|Reorder Point = ————————————— + S|
| Period Length |
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in which:
Dem.forec. = demand forecast
Oltm = order lead time
Oint = order interval
Sftm = safety time
S = safety stock
Period Length = (52 x 5)/number of periods
SEE ALSO KEYWORD(S)
– Item Issue by Period
– Item Issue by Warehouse
INFORMATION ABOUT DISPLAY FIELDS:
– Item