Subject: Oracle Manufacturing Lead Time Guide
Doc ID: Note:100127.1 Type: WHITE PAPER
Last Revision Date: 02-NOV-2007 Status: PUBLISHED
PURPOSE
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This document serves as a guide to Oracle Manufacturing Leadtimes. It answers
the following questions:
1. How are leadtimes, in Oracle manufacturing applications, used?
2. How are leadtimes maintained?
3. How do leadtimes impact other processes?
4. How are leadtimes defined?
SCOPE AND APPLICATION
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This document contains numerous facts and information on leadtimes used in
Oracle Manufacturing Applications and is intended for anyone having a need to
setup or understand the functionality of Oracle Manufacturing Leadtimes.
ORACLE MANUFACTURING LEADTIMES GUIDE
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1. BASIC MAINTENANCE.
a. The workday calendar must be setup correctly and rebuilt any time
modifications are made to the calendar.
Navigation paths: Bill of Materials/Setup/Calendars
Inventory/Setup/Organization/Calendars
b. Once you have made your modifications, you need to rebuild the calendar
by selecting the special option on the top tool bar. On the drop down list,
click on build.
c. Any time you make changes to a routing or resource, you should
recalculate and rollup the leadtimes.
Navigation path: Bill of Materials/Routings/Leadtimes
2. GENERAL FACTS
a. For an item to have manufacturing leadtimes calculated, it must be a
make item. Leadtimes are not calculated for purchased items even if they
have a routing.
1) Navigation path: Inventory/Items/Organization Items.
2) Select the General Planning alternate region.
3) Choose the make option for make or buy.
b. Set the scheduling option for the operation resources to yes.
1) Navigation path: Bill of Materials/Routings.
2) Put the cursor on the desired operation sequence.
3) Click on the [Operation Resources] button.
4) Select the desired resource sequence with your cursor.
5) Select the Scheduling alternate region.
6) Select the Yes option for schedule.
c. If you want to use a fixed leadtime for a resource, you need to use a
basis of Lot.
1) Navigation path: Bill of Materials/Routings.
2) Put the cursor on the desired operation sequence.
3) Click on the [Operation Resources] button.
4) Select the desired resource sequence with your cursor.
5) Select the Main alternate region.
6) Select the lot option for the basis.
d. If you want to use a variable leadtime for a resource, you need to use
a basis of Item.
1) Navigation path: Bill of Materials/Routings.
2) Put the cursor on the desired operation sequence.
3) Click on the [Operation Resources] button.
4) Select the desired resource sequence with your cursor.
5) Select the Main alternate region.
6) Select the item option for the basis.
e. If you put a number in the assigned units field, other than the number
1, which is defaulted, the scheduler will divide the leadtime for that
resource by the number of assigned units for the resource entered and use
the fractional leadtime in the leadtime roll up. The assigned units
field tells the scheduler how many resources/machines you have available
to the job in order to complete it in less time. In other words,
if you enter a 2, the leadtime for this resource will be cut in half.
If you enter a 3, the leadtime will be one third and so on.
1) Navigation path: Bill of Materials/Routings.
2) Put the cursor on the desired operation sequence.
3) Click on the [Operation Resources] button.
4) Select the desired resource sequence with your cursor.
5) Select the Scheduling alternate region. Here you can change the
number of assigned resources that you want for this resource.
f. MRP expects that you will receive material due into inventory by the
beginning of the business day on which it is due. You may wish to consider
receiving it into inventory at the close of business on the previous day.
Simply change your receiving function to accommodate this.
g. MRP will use the fixed leadtime if entered. This can be manually
entered into the organization item form in inventory.
Navigation path: Inventory/Items/Organization Items
h. Fixed leadtime is automatically entered if you do the Leadtime
Rollup. If you manually enter the fixed leadtime, it will be over-
written whenever someone does a leadtime rollup.
i. When doing a leadtime rollup, there is no validation for items if you
select a range of items. If you select a specific item, it validates
that item and, if it does not have a bill, it does not calculate any
leadtimes.
j. To set up a variable leadtime for a resource that can complete
one unit every ten minutes:
1) Navigate to Bill of Materials/Routings/Routings.
2) Query up a routing.
3) Put your cursor on the desired operation.
4) Click on the [Operation Resources] button.
5) Enter the resource sequence and the name of the resource that
will do the work.
6) Make sure the Unit of Measure (UOM) that defaults is correct.
In almost all cases it should be hour (HR).
7) Select Item from the drop down menu for basis.
8) Enter six (6) in the Inverse column under rate or amount. You have
now told the system that you can do six items per hour or one unit
every ten minutes.
k. Oracle WIP uses WIP Detailed Scheduling and Repetitive Line Scheduling
to determine order start date. Therefore, it is conceivable that MRP and
WIP could recommend different starting dates to meet the same requirement
due to the more refined method of order start date calculations in WIP.
l. Oracle starts calculating the leadtime at 12:00AM or the start time
of the first defined shift for the day.
m. The Oracle lead time calculation considers shift timing and gaps
betwen the shifts. Calculations are based upon the second.
n. Any time-based resource will be converted and rounded to the number of
seconds. The converted value has to be at least one second in order to be
calculated. The rounding to number of seconds is by design. For
non-time-based resources, the conversion rate is zero and will not have
any effect on leadtime calculations. For example, WIP (the application
which actually does the calculation), converts a usage rate of .000018 of
an hour to .0648 seconds (.000018 x 3600 second in an hour) which is then
rounded to 0. The code will not work if the precision is below a second.
This is standard functionality.
o. When doing forward scheduling, you have to schedule the resource
based on the shift hours (using start and stop times), workdays and
non-workdays, the start date and time of the lot and the usage rate of the
resource. In doing this, any elapsed or idle time, due to a resource not
being available to work, will be added to the leadtime. Depending on the
size of the lot being processed, you could have a wide variety of
completion dates and times. For example:
- You have a resource that can process one unit per hour and is
available from 8:00 to 4:00.
- A lot of three units will be moved to the next resource at 11:00.
The leadtime for this lot is .125 days for this resource.
- A lot of 10 cannot be moved to the next resource until 10:00 the
next day. This lot will then have a leadtime of 1.0833 days for
this resource.
p. Dynamic Leadtime Offsetting is the estimation of the start date of an
order, operation or a resource, based on the order quantity, leadtimes and
the workday calendar. Depending upon the number of units, volume and usage
rate, the leadtime could be rounded to zero.
q. Detailed Leadtime Scheduling calculates jobs to the second based on
resource units available and the usage rates.
r. Using a leadtime lot size greater than one will give a more accurate
variable leadtime. It should reflect the average lot size that will be
processed.
s. The Available 24 Hours checkbox on the resource schedule will ignore
manufacturing calendar days off if checked.
1) Navigation path: Bill of Materials/Routings.
2) Put the cursor on the desired operation sequence.
3) Click on the [Operation Sequence] button.
4) Select the desired resource sequence with your cursor.
5) Select the Scheduling alternate region.
t. Repetitive Line Leadtimes include:
1) Fixed line or routing based leadtimes.
2) Processing leadtime.
u. Calculating the Leadtime of Purchased Items.
1) Your workday calendar IS included when calculating any lead-
times for purchased items.
2) The purchased items leadtime is calculated as follows:
Postprocessing Leadtime (time needed to move from receiving
to inventory)
+
Processing Leadtime (time vendor needs the order before
delivery to your dock)
+
Preprocessing Leadtime (purchase order preparation)
3) The results are:
The dock date (found on the Planning Detail Report) is the date
by which the vendor should deliver the material to your dock.
Dock Date = Order Due Date - Postprocessing Leadtime
The start date is the date by which you should give the sales
order to your vendor.
Start Date = Dock Date - Processing Leadtime
The order date is the date by which you should start your
purchase order.
Order Date = Start Date - Preprocessing Leadtime
4) You can assign values for fixed leadtime instead of assigning
the processing leadtime.
v. Calculating the Leadtime of Manufactured Items:
1) Fixed Leadtime (time your shop floor needs to manufacture the
item or complete the job).
Fixed leadtime =
lot time (usage rate or amount) / assigned units
2) Variable Leadtime (time your shop floor needs to manufacture
each item - each piece * variable leadtime)
Variable leadtime =
total lot time + ((item based time * lot size) assigned units)
3) The planned order order date is the date by which you need to
start the process of creating a discrete job or repetitive line.
It is calculated as follows:
Planned order order date =
planned order order date - preprocessing leadtime
4) The planned order due date is the date by which the item is needed.
It is similar to the dock date for a purchased item.
5) The planned order start date is the date by which you need to
release a discrete job or start a line. It is calculated as
follows:
Planned order start date =
planned order due date - leadtime offset
The leadtime offset is used as follows:
Planned order due date - leadtime offset =
planned order order date
The leadtime offset is calculated as follows:
Leadtime offset =
Fixed Leadtime + (Variable Leadtime * Order Quantity)
