Finite Capacity Planning (SAP Library - Supply Network Planning Run)

Finite Capacity Planning

Purpose

It is particularly advisable to use the SNP optimizer to plan capacities as finite if you have limited business resource capacities and these limited capacities have an impact on your production planning and distribution resource planning. By already planning capacities as finite in Supply Network Planning (SNP), you can take capacities into account and make it easier for the subsequent detailed scheduling (such as SAP APO Production Planning and Detailed Scheduling, PP/DS) to create feasible plans.

Furthermore, by using the SNP optimizer to plan finite capacities, you can include a possible extension of your capacities into your plan, subject to the calculation of additional costs.

You can use the SNP optimizer to plan the following resource categories and types as finite:

· Resource categories:

¡ Production resources

¡ Transportation resources

¡ Handling resources

¡ Storage resources

· Resource types:

¡ Single-mixed and multimixed resources

¡ Bucket resources

¡ Transportation resources

Integration

The SNP optimizer takes into account the net available capacity only, meaning that it checks whether the capacity available in SNP is already being used by other system application areas (PP/DS, deployment, or the Transport Load Builder, for example) or by fixed SNP orders.

For single-mixed and multimixed resources, the SNP optimizer subtracts the capacity consumed by PP/DS, for instance, from the capacity available in SNP. If the capacity consumed by PP/DS exceeds the aggregated available capacity in a bucket in SNP, the optimizer assumes that there is an available capacity of 0 in the corresponding bucket and plans no further capacity consumption in this bucket.

Prerequisites

The prerequisites for finite capacity planning are the same as those for general optimization-based planning:

· Planning Area Administration

· Master Data Setup for the Optimizer

· Model/Version Creation

· Supply Chain Model Setup

· Release of the Demand Plan to SNP

Features of Finite Capacity Planning

General Information

· Generally, the SNP optimizer takes into account all model constraints simultaneously. This means that the optimizer takes into account the available capacity of all resources at the same time. Thus, during multilevel production, for example, all the manufacturing levels are incorporated simultaneously into planning.

In the SNP optimizer profile, you can set which capacity constraints (production capacity, transportation capacity, handling capacity, or storage capacity) you want the optimizer to take into account.

· The optimizer determines the available capacity based on the defined factory calendar, meaning that it only uses days defined as workdays to determine the bucket capacity.

· You can define multiple capacity variants for resources and label these as the minimum, normal, or maximum available capacity. Thus, you can let the optimizer decide to increase capacity or fall below the minimum capacity subject to the calculation of additional costs. Since the optimizer generally chooses the solution with the lowest costs, it will only increase capacity or fall below the minimum if this course of action is the most cost-effective total solution despite the additional costs.

You define the costs for the capacity variants with minimum, normal, or maximum capacity in the quantities/rate definition or the capacity profile of the resource master data. To set the status indicator, go to the resource initial screen and choose: Current Settings -> Capacity Variants (see also, Master Data Setup for the Optimizer).

Note that the optimizer takes into account the minimum available capacity and the costs you defined for a capacity variant with the status Normal Capacity only for production resources.

Production Resources

Capacity Consumption

· The SNP optimizer takes into account the capacity consumption of a production resource, which you define in the production process model (PPM) mode. One PPM can load several resources and one resource can be loaded by several PPMs. The duration of an SNP PPM (that is, the sum of the duration of all PPM activities) is fixed. It has no influence on resource consumption and instead is used only for scheduling within the PPM.

The resource consumption defined per activity is distributed evenly over the length of the activities. This means that the optimizer ignores the consumption type defined for the activity and always assumes that consumption is continuous (consumption type C).

· If you use the linear optimization method, the optimizer only takes into account the variable resource consumption defined in the PPM. If you want the optimizer to also take into account fixed resource consumption, you have to choose discrete optimization in the SNP optimizer profile and define a discretization horizon for the Fixed Material and Resource Consumption. This is necessary if, for instance, you want to use fixed resource consumption to model setup times during lot size planning with the SNP optimizer (see also, Lot Size Planning).

Note

Note that the optimizer ignores the fixed resource consumption defined in the PPM if you choose the linear optimization method in the SNP optimizer profile. However, fixed resource consumption is taken into account if orders are created in liveCache during planning. This can cause a resource overload to be displayed in the capacity view of interactive Supply Network Planning. Therefore, if you want the optimizer to take into account the fixed resource consumption, choose discrete optimization or do not define a fixed resource consumption in the PPM.

If you are running an integrated SNP and PP/DS planning and set the Lot Size Planning: Not Cross-Period indicator in the SNP optimizer profile (the Integration tab page), fixed resource consumption is not taken into account when creating SNP orders in liveCache if there is already an existing PP/DS order for the associated PP/DS PPM (see also the F1 help at the indicator). This also applies for Cross-Period Lot Size Planning if you set the accompanying Cross-Period Lot Size Planning indicator.

· The optimizer also takes into account time-based resource consumption that you defined in the PPM. You can use time-based consumption to model varying consumption levels over the course of the bucket. For example, you could include the following information in your plan: A machine consumes more lubricant at the beginning of production than it does towards the end.

Available Capacity

· For the maximum available capacity variant of production resources (see above), you can define that the optimizer is permitted to either increase the capacity by this variant’s entire available capacity (an entire layer, for example), or not increase it at all. In this instance, the optimizer either takes into account the entire costs of the increase or no costs at all. In the SNP optimizer profile, choose the discrete optimization method and define a discretization horizon in the Discrete Production Capacity Increase field.

Capacity Costs

· You can also define time-based costs for increasing the capacity of production resources. For a daily planning buckets profile, you can define that the increase costs more on a Monday than it does on a Tuesday, for example.

· You also have the option of defining costs for the normal capacity variant (standard capacity) for production resources. You can specify these costs (also on a time basis) per capacity unit and bucket. The costs incurred are proportional to the resource usage.

· If you wish to define a minimum available capacity (see the General Information section), you have to define costs for falling below it. You can also specify these costs for each capacity unit and bucket. The costs incurred are proportional to the amount fallen below the minimum available capacity.

Constraints

· Since you can only create one mode per activity in the SNP PPM, you cannot define any alternative resources for a production activity. To define alternative resources, you must create one PPM per mode combination. You can use the SNP PPM Generation With Lot Size Margin function to generate SNP PPMs automatically for multiple PP/DS PPM mode combinations.

Transportation Resources

Capacity Consumption

· The SNP optimizer only takes into account the means of transport’s variable capacity consumption (per day) that you specified in the Consumption field of the Product-Specific Means of Transport section. You specify consumption for the product that is defined in this section. Consumption is dependent on the transportation duration. If the transportation duration is 0, no resource consumption exists.

If you do not enter a value in the Consumption field or do not define any data for the Product-Specific Means of Transport, the optimizer calculates consumption using the conversion factor for units of measure that you specified on the Units of Measure tab page in product master data.

Available Capacity

· You can assign transportation resources to multiple transportation lanes and so limit the transportation capacity on these transportation lanes. To do this, specify a transportation resource in the Resource field of the Means of Transport section in the transportation lane.

· In the SNP optimizer profile, you can set that you want the available means of transport to be treated as discrete (in non-divisible integer numbers). If you do this, the means of transport is treated as discrete for each transportation lane. You define the capacity of the means of transport in the Transp.Res.Size field of the resource master data.

You can use this option to model the means of transport that are available in your company (a truck, for example). However, if you commission external transportation service providers, considering means of transport as discrete is not relevant for you.

Capacity Costs

· The transportation costs considered by the optimizer consist of the product-specific transportation costs (that is, the transportation costs you entered in the Product-Specific Means of Transport section in the transportation lane) and the transportation costs for the means of transport (that is, the transportation costs entered in the Means of Transport section). The means of transport costs are dependent on the transportation resource consumption of all the products transported on the transportation lane and the distance that was defined for the transportation lane between the start location and destination location.

· You can define the means of transport costs either as costs per transportation resource unit or as costs per means of transport. For the costs per transportation resource unit, you do not define a size for the transportation resource. However, for the costs per means of transport, you do define a size (5 t, for example) and set the Integral Means of Transport indicator in the SNP optimizer profile, if required (when activating this indicator, you must also choose the discrete optimization method in the SNP optimizer profile).

If, for instance, you want to model discount scales for the costs per transportation resource unit option, you can use cost functions. Cost functions are most appropriate when you are working together with external transportation service providers.

Handling Resources

Capacity Consumption

· You can assign handling units to a location (on the Resources tab page) as handling-in resources or handling-out resources in location master data. The handling-in resource is loaded by inbound shipments (SNP stock transfers) and external procurement during the goods receipt processing time and the handling-out resource is loaded by outbound shipments during the goods issue processing time.

· You can define the capacity consumption of the handling-in and handling-out resources for the respective location product in location product master data (on the GR/GI tab page). Resource consumption refers to the handling operation and is therefore proportional to quantity but not time.

Constraints

· You can define a maximum of one handling-in resource and one handling-out resource per location.

Storage Resources

Capacity Consumption

· The optimizer takes into account the capacity consumption of the storage resource that you define for the respective location product in location product master data (on the GR/GI tab page).

Available Capacity

· The optimizer considers the storage capacity constraint as a soft constraint that can be violated by the optimizer, subject to the calculation of penalty costs. These penalty costs are assigned by the optimizer, which means that you cannot set them in the master data.

Storage capacity is a soft constraint due to the integration between Supply Network Planning, PP/DS, and SAP R/3. There might be initial on-hand stocks or fixed material receipts (from PP/DS, for example) because of this integration that cannot be reduced within a bucket and exceed the storage capacity. To be able to find a solution, the optimizer must be allowed to violate the storage capacity and incur penalty costs. However, due to the high penalty costs incurred, the optimizer will always try not to exceed the storage capacity.

· In contrast to other resource categories, the available capacity of the storage resource is not aggregated by bucket. The optimizer always takes into account the capacity that is available on the final day of a bucket.

For the storage resource, we recommend that you choose a factory calendar with no non-working days. If the final day of a bucket were a non-working day, the optimizer would assume an available capacity of 0.

· In addition to the storage resource capacity, you can define a product-specific upper bound for on-hand stock in the location product master. The optimizer takes this upper bound into account if you set the Maximum Product-Specific Quantity Stored indicator in the SNP optimizer profile. The optimizer considers this a soft constraint, meaning that it can be violated subject to the calculation of penalty costs. These penalty costs are assigned by the optimizer, which means that you cannot set them in the master data.

You can also define a time-based upper bound for stock. For more information about this, see Definition of Time-Based Constraints in Interactive Planning.

Constraints

· You can assign a maximum of one storage resource to each location.