Check of capacity availability

The basic principle for operations is that the CDT CDT is short for check delivery times and it is a function on order rows which calculates when the order row in question can be delivered, taking lead times and throughput times into consideration. CDT also checks if existing orders and suggestions can cover material shortages, if any, and affects when the order row can be delivered. function checks the available capacity in the future, that is, when the earliest possible time is to start each operation, if manufacturing is needed. If an operation for example takes four hours, the CDT will look in the future for four hours available capacity in a row.

For work centers with the time precision set to Day planning Day planning is used when you are NOT applying hourly planning. It means that all operations are planned to a date and not to a specific time on a date., the CDT function will check for these four hours on day level, that is the CDT will analyze the available capacity/loading per day. For work centers with the time precision set to Capacity via schedule or Hourly planning Hourly planning refers to when planning per work center is done per hour. Hourly planning is activated with a system setting. Period is then entered as date and time. You can view loading on hour basis., the CDT function will check for these four uninterrupted hours in the defined schedule.

The system setting Time when order day/start day changes to next day determines if the capacity is available during the day or the next day.

The calculation of when an operation can be performed also considers the work center's availability factor. If the work center fore example have an 80% availability and it is an operation which takes 8 hours, then the CDT must find 10 hours of uninterrupted capacity (8 ∕ 0.8) in the schedule of the work center. The operation can in that case not be planned to be completed on a schedule with eight hours.

The CDT function also takes lag in the loading plan into consideration. The hours of the lag is then added to other loading – which is not lag – and affects when there is capacity available.

Overload, if any, is evened out and is included in the CDT. This gives the same effect as a lag does, that is, the overload will be included and calculated together with other loading. In the loading plan you can compare the row for Accumulated difference including lag with the available capacity in this calculation. Where a positive difference occurs the CDT function starts looking for available capacity.

When the analysis has been made for each separate operation, the CDT has found an earliest finish date for each operation. These dates does not have a relation to each other. This might cause them to no be in phase. For example, the first operation might get the earliest finish date April 14, 2022, and the second operation can get an earliest finish date of April 12, 2022. But this is not the order in which the operations should run. Each operation has a difference between the finish date it should have had if you placed the order for the planned date and the earliest possible finish date that the CDT has reached. The difference is given in work days for operations with day planning and in hours for operations with hourly planning. This difference can be both positive (possible to run the operation earlier than planned) and negative (the operation should be run later than planned). The operation with the largest negative difference (or the smallest positive) is the operation which is critical.

The CDT keeps checking if all other operations can be planned in the right time/order in relation to the critical operation. It might be the case that the operations before and after do not have sufficient capacity at that time. Then the CDT function will look for new earliest finish dates for the operations. This is repeated until all operations have capacity and can be run in the correct sequence with the correct number of queue days in between. The analysis is then completed and the CDT has found a finish time for the final operation which is the date when you should be able to have the part ready for delivery. This is called a "puzzle difference". However, no consideration has yet been taken to the material availability.

In the result window the critical operation is indicated with a light red color to make it clear to you which operation has been governing for the finish date. By allocating more capacity to that operation you can affect the finish date.

Regarding work centers of the Pool type, the loading from the pool and the included work centers is combined and compared to the total capacity for the included work centers. This provides a complete loading for the work centers and can thereby be used to search for available capacity for additional loading. This means you will get the same result regardless if you have created BOM and routing for a pool work center or directly for one of the included work centers.

Another step in the calculation of capacity availability concerns suggesting an alternative work center instead of the regular work center. Alternative work centers can be linked on operations in the BOM and routing. The CDT function suggests to change work center for the critical operation. The suggested work center and new finish date/delivery date provided when that work center is used can be seen and confirmed in the result window.

You can also manually change to an alternative work center in the result window and run the CDT again using the new work center. However, manual replanning items are not saved so you have to manually perform the same replanning after the manufacturing order is created. Both when the CDT provides suggestions of alternative work centers and when you manually change work center in the result window, a new calculation is done. When you confirm your selection in the result window the standard price, CM The contribution margin (CM) is the difference between the standard price and the sales price. and CR The contribution ratio (CR) is the portion of the invoice amount (sales price) that the contribution margin represents. CR is entered as a percentage., will also be updated on the order row as a result of the calculation.