This guide explains some lead time basics and provides example problems and solutions.
Lead Times
This Lead Times chart comes from Appendix B of the Core User Manual, and provides a summary of the functionality:
When Customer Lead Times and Product Lead Times are used together, FeneVision uses the longer of the two values. This applies to final shipments when there is a transfer shipment involved.
Customer Lead Time – Lead time specified per customer in Customer Setup.
Product Lead Time – Each line item has its own lead time associated with it based on the configured lead times for the part and options selected. This is called the line item’s Product Lead Time. The Product Lead Time is the number of working days it takes to fully produce an item from the time it is ordered. This includes the time spent ordering any materials needed, as well as the time it spends in production. If an order has more than one line-item, the largest of these is the order’s Product Lead Time.
Create a new order – If the Customer Lead Time is greater than zero when an order is first created, the Required Date is set that number of workdays after the current date.
Placing Line Items on the Order – As the user adds line items to the order the system calculates the Product Lead Time of each line item and compares it to the Customer Lead Time. The required date is recalculated using the largest value between the Customer Lead Time and each line item’s Product Lead Time.
After calculating the required date, the system attempts to set the Target Ship Date. If the Target Ship Date does not fall on a valid shipping day for this customer, it is moved to the next valid ship date. The Required Date moves along with it.
Note: If the Required Date is calculated using the Customer Lead Time, capacity Blocked Dates are ignored. If the Product Lead Time is used, capacity Blocked Dates are considered.
Acknowledge the order – If the following setup parameters are present, ReqDateCalcOnAck and ReqDateCalcOnAckPrompt, the required date will recalculate when the order is acknowledged. The required date calculates from the acknowledge date by taking the largest lead time between the Customer Lead Time and each line item’s Product Lead Time. If the required date is overridden, the user will be prompted to reset it.
Manufacturing Lead Time – In addition to the Product Lead Time each line item can have its own Manufacturing Lead Time, as well. The Manufacturing Lead Time is the number of working days it takes to fully produce the line item after it is released to production. Therefore, the Manufacturing Lead Time should never be larger than the Product Lead Time.
Note: If the Manufacturing Lead Time is NOT set, then it takes the value of the Product Lead Time.
Plan Date – The Plan Date is the date by which the order must be released to production to be ready by the Target Ship Date. After the order’s Required Date and Target Ship Date are calculated, the Plan Date is calculated. This is calculated one of two ways. If the Capacity Planning Module is being used and the Planning Direction is set to Backwards from Target Ship Date, then capacity plans backwards and the line item’s Plan Date is set as the first day it is planned at a work cell. If capacity planning is not being used or the Planning Direction is set to Forward from Plan Date, the Plan Date is set by taking Manufacturing Lead Time and moving back that number of days from the Target Ship Date.
For example, a shipping route ships on Tuesdays and Fridays. Today is Monday. One line-item on an order has a lead time of 2 days, while the second line-item has a lead–time of 3 days. The maximum lead time is 3 days, which falls on a Thursday (not a shipping day), so the target ship date is Friday. The line-item with a 2-day lead time will not need to be manufactured until 2 days before shipment, which is Wednesday. This is the Plan Date. The line-item with a 3-day lead time will need to be scheduled for Tuesday.
Cutoff Time – If the ReqDateCutoffTime setup parameter is in use, any order entered after the specified cutoff time will use the next business day as the basis for the date calculations, instead of the current date.
Example, if today is Thursday, the largest lead time is 3 days, and the customer ships every day. The Target Ship Date would be Tuesday. (Friday = 1, Monday = 2, Tuesday=3).
However, if the setup parameter ReqDateCutoffTime is enabled, and the timestamp on the order’s date is greater than the setup parameter value, then the first day to check is pushed back one day. In the above example, if the order missed the cutoff time, then the Target Ship Date would be Wednesday (Monday = 1, Tuesday = 2, Wednesday = 3). By default, the cutoff time is only applied when the order is not yet acknowledged. To use the same cutoff time after the order has been acknowledged, the ReqDateUseCuttoffTimeAfterAck setup parameter must be enabled.
New Required Date – Once the new required date has been calculated, it is automatically set for the order. If the required date has been previously overridden, the user will be prompted with the option of resetting the required date. If the user selects ‘No’, the required date will remain the same, and the question will not be asked again.
Change the Route on an Order – The shipping route assigned to the order can be changed at any time. When the route is changed, the required date will automatically recalculate using today’s date and the ship days defined on the new route. If the required date was previously overridden, the user will be prompted with the option of resetting the required date. If the user selects ‘No’, the required date will remain the same, and the question will not be asked again until they leave the order.
Change the Status of an Order – When the status of an order is changed from On Hold to Available, the required date is recalculated using today’s date. If the recalculated date is different from the current required date, or the required date was overridden, the user is prompted with the option of resetting the required date. If the user selects ‘No’, the required date will remain the same, and the question will not be asked again until they leave the order.
If utilizing the FeneVision Capacity Planning application, the exception dates are also taken into account when calculating the required date.
FAQ and Examples
How does cutoff day impact lead time?
The system calculates the required date using two different methods, depending on whether the customer Order Cutoff Day is set to {None} or not. You can find the cutoff day on the General tab of the Customer Setup screen.
If the cutoff day is set, the system calculates the required date solely based on the cutoff day and lead time. In this case, none of the shipping settings are considered, including two-day routes, multiple ship days per week, or blocked dates.
If the cutoff day is not set, the system uses the assigned route to find the earliest ship date available. It takes the greater lead time between the customer and the part lead time, adds that to today's date, then looks for the next ship day on the assigned route. The required date is then calculated by adding the number of ship days (0 for a one-day route, 1 for a two-day route) to the ship date.
What GSPs can affect required date calculation?
ReqDateCutoffTime - String value used to set the cutoff time of day for the required date calculation routines. Orders placed through Core or Web after the cutoff time indicated will start with the next business day being the first lead time day instead of the current day. Time formatted in 12-hour format (i.e., 5:00 PM).
ReqDateUseCuttoffTimeAfterAck - Boolean value. When true, the cutoff time (specified in “ReqDateCutoffTime”) is used even after the order has been acknowledged (or if required date is calculated during acknowledgment.) By default, the cutoff time is only applied when the acknowledge date has not been set.
Why are customers with 0 lead time generating required dates of 14 days?
The required date was bumped out because the product lead time was set.
I need an extra day for my Stage cell before shipping.
Try adjusting the Normal and Fast settings in Capacity. In this case, changing Normal from 1 to 2 solved the issue.
- Normal – Lead time under normal production. Indicates the standard number of shifts it takes to do work within a work cell. This number can be between 0 and 45. For example, at the PAINTING work cell, it typically takes two-and-a-half shifts to complete work, so the user will enter 2.5 as the normal lead time.
- Fast – Lead time under rush production. Indicates the quickest number of shifts an item can be processed at this work cell. This number can be between 0 and 45. For example, given a rushed situation at the work cell PAINTING, the item can be completed in one less shift than as in ‘Normal’; therefore, it would take one-and-a-half shifts to complete work. The user enters 1.5 as the fast lead time.
Why am I getting a capacity exceeded message when I am not over capacity?
- This can happen if the target ship date for the order was overridden (target ship date is bold).
- As soon as a line item is created it will be assigned its default capacity. After that, capacity will be assigned with each new line item you add. However, if you manually move capacity to a different date (which is not over capacity) the order will NOT recalculate the capacity, otherwise it would do so for every single movement you do, which in the long run would take way too long. There are 2 points to consider with this:
1) when you would release this order into production, a second calculation would be done, in which the errors would disappear (if you are not over capacity),
2) if you would perform a recalculation of any line item, the error would also disappear if you are not over capacity (if you do not maintain the original capacity).
- As soon as a line item is created it will be assigned its default capacity. After that, capacity will be assigned with each new line item you add. However, if you manually move capacity to a different date (which is not over capacity) the order will NOT recalculate the capacity, otherwise it would do so for every single movement you do, which in the long run would take way too long. There are 2 points to consider with this:
- This can happen for un-acknowledged orders and orders with hold policies. In Capacity Planning Settings, use the "Plans on hold until acknowledgement" setting and check "Plans On Hold" for related policies to place capacity on hold for these types of orders.
- This can happen if the target ship date for the order was overridden (target ship date is bold).
Why do we have plan dates that are going over the Capacity allocation for a given planning work cell?
This can be seen when units were manually moved in capacity, and if they were manually moved, they would appear in BOLD in Capacity Requirements.
When planning, the system looks at lead time and capacity type. There are 4 steps: normal-standard, normal-maximum, fast-standard, and fast-maximum. If none of these are able to be planned, the system plans under the fast lead time regardless of the capacity type (ignores capacity limits). Therefore, lead time of Fast and capacity type of None means it couldn't plan the unit under the normal plans.
My glass unit is not proceeding through capacity.
The glass part may be missing the "glass" and "capacity" part types in Part Setup on the Part Types tab.
When replan on schedule release is enabled does enforce capacity still apply?
- No, when replan on schedule release is enabled enforce capacity does NOT still apply, per the user manual.
- Replan on Schedule Release – Every item on the schedule is re-planned forward from the release date. Replan on Schedule Release plans take priority over Order Entry plans. Therefore, it is possible for an item to be planned at a work cell where capacity has already reached its maximum, as long as some of the planned items have not been released to production. As a result, even if Enforce Capacities During Planning is enabled, users may see overbooked work cells until everything has been released to production.
- No, when replan on schedule release is enabled enforce capacity does NOT still apply, per the user manual.
- How are "working days" determined?
- The Shifts that are configured in the Capacity Setup screen are used to determine which days are working days. If a shift is present, that day is considered a working day.