Re: Backward vs Forward Scheduling

Gerry,

I'm testing this in detail and I'm just a bit confused on when to decide
if the run time takes its own DAY, or when the RUN time IS INCLUDED
in/on a Queue day?

Thanks,
Don C.

-----Original Message-----
From: bpcs-l-bounces+dcavaiani=amerequip.com@xxxxxxxxxxxx
[mailto:bpcs-l-bounces+dcavaiani=amerequip.com@xxxxxxxxxxxx] On Behalf
Of Gerry Duhon
Sent: Monday, October 08, 2007 2:54 AM
To: bpcs-l@xxxxxxxxxxxx
Subject: [BPCS-L] Backward vs Forward Scheduling


Backward vs Forward Scheduling

Orders are Backward Scheduled when given a Due Date and are Forward
Scheduled when given a Start Date

Operations are automatically backward scheduled at shop order release
time. The backward scheduling algorithm starts with the shop order due
date and schedules each operation based upon the standard move and queue
times in the routings and the number of days the job is expected to run
at standard. The system calculates and stores the operation scheduled
start date. The dates may be modified by the Shop Order Maintenance
application. The number of days that a job is expected to run an
operation is dependent upon the available capacity for that work center
and the total hours scheduled for that operation.

Any calculated slack time is placed at the beginning of the process.
BPCS considers the shop calendar and any weekends, holidays, or other
non work days when backward scheduling.

Backward Scheduling Process,

The algorithm starts with the due date of the shop order or planned
order. Then for each operation in reverse sequence, the following
calculations are made:

* The number of move days is subtracted from the due date (or
initial date of the previous operation) to get the due date for this
operation. The move days are only used on valid shop calendar days.

* The number of clock hours for the operation is calculated as:

* standard run or machine hrs / # operators + setup hours

* The number of clock hours is spread over the available daily
capacity of the work center for those given days. The daily capacity of
the work center is calculated as: # shifts * hours per shift * average
efficiency / 100

* Each day is checked against the shop calendar; the calculation
will bypass inactive days or adjust for any changes in the work center
capacity for that day.

* Queue time days are subtracted in the same manner as move time
days. The resulting date is the operation start date.

The algorithm then goes to the previous operation. When all operations
have been included, the resulting date is the scheduled start date the
shop order. Note that Material Requirements Planning uses the item lead
time to determine material requirement dates on planned orders.

If a new Planned Order, Firm Planned Order or Shop Order is created
without a due date, BPCS will go through the scheduling logic to create
a due date.

Firm Planned Orders (FPO) are a signal to Master Production Scheduling
(MPS)that you are taking control of the timing and quantity planned for
an item; usually in anticipation of future demand. Unlike Planned
Orders, Master Production Scheduling will not cancel/revise the due date
and quantity of an FPO in response to changes in demand or planning
parameters in Item Planning Maintenance (MRP140). MPS suggests releases
and rescheduling of firm planned orders but does not automatically
reschedule as part of the netting logic. However, you will receive the
appropriate action message detailing suggested actions.

FPOs can be created in Planned Order Maintenance (MRP510) or in MRP
Workbench (MRP570). A system parameter determines whether to use FPO in
the Available to Promise (ATP) calculations. Component inventory can not
be allocated to either Firm Planned Orders or Planned Orders. If you
have a requirement to allocate scarce components, you must create a shop
order.

Best Regards,

Gerry Duhon | Sr. Application Consult ant | Professional Services Infor
| Cell815.347.0754 |Gerry.Duhon@xxxxxxxxx -----Original Message-----


1. FW: Sandbox Warrior Team Meeting- fwd. vs backward schedueing
(Don Cavaiani)
2. Re: FW: Sandbox Warrior Team Meeting- fwd. vs backward
schedueing (Al Mac)
3. Re: We are plugging Lead Times (Al Mac)


----------------------------------------------------------------------

message: 1
date: Fri, 5 Oct 2007 18:38:23 -0500
from: "Don Cavaiani" <dcavaiani@xxxxxxxxxxxxx>
subject: [BPCS-L] FW: Sandbox Warrior Team Meeting- fwd. vs backward
schedueing

This is fairly complicated - please comment if you would.

Thanks,
Don