These values are automatically computed by the system when you run the following jobs:

Calculate Cumulative and Unprotected Lead Time

Explanation

This activity is used to calculate a part’s cumulative and unprotected lead times. The cumulative lead time of a part is the total turnaround time for all parts in the structure. You can calculate the cumulative lead time for a single part or all parts for the specified site.

Use the Cumulative Lead Time Calculation page to calculate the cumulative lead time of a specific part or all parts in a site.

• When calculating the cumulative lead time for asingle part, it looks just one level down and accumulates the lead time tothe top.It does not consider the entire BOM structure.
• When calculating the cumulative lead time for all parts in a site, itstarts with calculating low level code, then it calculates the cumulative leadtime for the parts on the lowest level and then it continues with parts on(lowest level - 1) etc. This always gives accurate results.

Specify whether you want to perform a calculation for all parts in a site or for one part at a time. In either case, the lead time calculation only uses the default '*' alternate. Only alternates in the Planned or Buildable states are used. While this job is running it calculates the Unprotected lead time of a specific part or all parts in a site. Unprotected lead time for a single part, it looks just one level down and accumulates the lead time to the top. It does not consider the entire BOM structure. It evaluates whether the parts exist in a critical part of the product structure considering the unprotected lead time. Lead time category classification is also triggered for parts with planning method H.

Note: Safety lead time of the parts excluding planning method B, C, O, T, K, P or H will be included as a component in respective cumulative lead time.

Note: Parts added as direct supply in a Remanufacturing type structure are not considered in the cumulative lead time calculation.

Routing Lead Time Calculation

General Information

The routing lead time calculation can be done for the current and future revisions and for all routing alternates for a part. The calculation considers setup, transport and operation times, efficiency factor, overlap and eventually also operation quantity factor entered for the operations. The calculation also considers the information about queue time and shifts such as the number of work hours per day from the work center where the operation is performed. You can run the calculation for one part at a time or for all parts in a specific site. Optionally the inventory part can be updated with the lead time calculated for the default routing alternate (*) and the current revision.

The lot size on which the lead time calculation is based, is normally the standard lot size specified on the inventory part. It is possible to simulate lead time for other lot sizes using Calculate Lead Time from the Routing, Routing Alternate or Routing Alternates pages.

Routing lead time calculations can be based on machine time, labor time or the maximum of machine and labor time. The work center capacity used in the calculation can be either the demonstrated capacity or the average capacity as specified on the work center. The average capacity represents the projected usage based on the current work center parameters. The demonstrated capacity represents the past actual usage.

Routing lead time is used in several places like in IFS/Material Requirements Planning (MRP) and IFS/Master Scheduling (MS) when creating supply.

Fixed and Variable Lead Times

The fixed lead time is the time that does not vary based on the lot size. For a routing alternate having no parallel or overlapping operations, the fixed lead time is the sum of setup time, transport time and queue time for all operations.

The variable lead time is the time that is needed for each unit produced. For a routing alternate having no parallel or overlapping operations, the variable lead time is the sum of machine or labor time for all operations.

For parallel operations only the operation that takes the longest to complete will be considered when calculating the fixed and variable lead time. For an operation that overlaps with the previous operation the contribution depends on the overlap and the difference in run time between the operations.

Formula for Routing Lead Time Calculation

The formula below is used when calculating routing lead time. The formula does not cover calculations for operations with overlap. For parallel operations only the operation with the longest lead time will be considered.

Where:

• Setup time = Time entered on each operation of the routing.
• Run time = Time entered on each operation of the routing.
• Lot Size = The standard lot size of the inventory part. If an Operation Qty Factor is defined, that percentage of the standard lot size is used.
• Operation efficiency = Time entered on each operation of the routing.
• Work Center Capacity = The average or demonstrated capacity entered on the work centers.
• Transportation time = Time entered on each operation in the routing.
• Site Manufacturing Calendar Hour = Average number of working hours on a work day for the site manufacturing calendar.
• Queue time = Time entered on the work centers
• Work Center Calendar Hour = The number of working hours on the work center on the day the calculation is performed.

I hope that this helps.

Thanks for your extensive answer. We never worked with this in the past, so it will cost some time to completely understand all described above. Maybe I need to state where we need this for: We want to know for our shoporder planning a start picking date based on the external leadtime + the transport leadtime to our turnkey partner + picking leadtime calculated back from the need date in the shoporder.  I have set a value in the Mach Setup to have the demand for the materials earlier visible in my planning. But it does not help our warehouse in deciding a clear cut off date to start picking the materials. I am not sure if this is the best way. I hope you can shed a light to this.

Hi,

I think you are on the right lines here and essentially you need to do the following things for the complete solution.

Make sure you enter Supplier Manufacturing Lead Time against the Supplier for Purchase Part records for each of the shop order components.

You can also include Inspection Time 

Add External Delivery Time and Internal Transport Time in Supply Chain Matrix for Site

Run the Calculate Purchase Lead Time job

This calculates the Purchase Lead Time for all of the component parts.

Create a Routing for your manufactured part and add operations. 

The Work Centre, Machine Set Up, Machine Run Factor and Factor Unit can be used to specify where the operation takes place and how long the operation takes to perform.

Run the Manufacturing Lead Time Calculation

This calculates the Manufacturing Lead Time for the manufactured part.

Run the Cumulative Lead Time Calculation

This calculates the Cumulative Lead Time for the parts.

Look at the Product Structure for the manufactured part.  It is possible to connect the component parts to specific routing operations.

This means that when a Shop Order is created, the component material required date is based on the scheduled start date/time of the shop order operation rather than the shop order Need Date.

This information can then be used when planning when to pick the component parts.

I hope this helps.

Very extensive tips, many thanks. I can say we have several parameters already in IFS, but some indeed not. Let me get this setup in IFS test to get a good simulation