Supply control or safety stock planning is required to manage the uncertainties in the supply chain. Safety stock planning is an integral part of the supply planning process, which is used to determine the optimal safety stock quantity and safety stock location. The optimal deployment of the stock is crucial for any business.
As the supply chain becomes complex, so do the factors that can influence the safety stock planning in the supply chain. When managing hundreds of products distributed across several locations in the enterprise, you should have an optimal safety stock to avoid excess stock at each level of the supply chain. Although it’s required to maximize the service level requirements by planning for sufficient safety stock at all levels of the supply chain, having such a strategy isn’t feasible from the cost perspective. The goal of multilevel safety stock planning is to meet the end user customer service levels with optimal stock in various locations of the supply chain. By using the safety stock planning methods available in SAP SCM, you can create optimal safety stock.
Standard and extended safety stock planning methods are available in SAP SCM.
Using standard methods, it’s possible to define the safety stock quantity and loca-tion based on the planner’s experience or using third-party inventory optimiza-tion tools. Extended safety stock planning methods in SAP SCM are available to calculate the optimal safety stock for a given service level using alpha and beta service level methods.
Safety stock planning in CTM is available for the standard safety stock methods.
CTM generates the constrained supply plan using the safety stock requirements maintained for the products. The extended safety stock methods aren’t supported in CTM planning. Safety stock planning in CTM can be used to create the supply plan based on the required safety stock (SS) or using the safety days of supply
(SDS) to create the supply plan for future requirements. Additionally, using the supply distribution (SD) function in CTM, it’s possible to deploy excess stock in the next level of the supply chain using the outbound quota values. Supply control for the dependent requirements can be achieved using the Maximum Earliness parameter in CTM planning. In the SC Model where the storage of products isn’t desired at the production plant, CTM planning offers functionality to store the products at the distribution location instead. With SAP SCM 5.1, you can build a supply for a given product location based on the minimum build (MB) require-ments. This is useful in scenarios where special contractual agreements exist for the subcontractors.
The standard SS planning methods that are available in SAP SCM are defi ned indi-vidually for each product location in the product master as shown in Figure 5.1.
Safety Stock Planning Methods Figure 5.1
The following SS methods are available in SAP SCM:
SB
E E
Safety Stock from Location Product Master MB
E E
Safety Stock (Time-Based Maintenance) SZ
E E
Safety Days’ Supply from Location Product Master
MZ
E E
Safety Days’ Supply (Time-Based Maintenance) SM
E E
Max. of Safety Stock and Safety Days’ Supply from Location Product Master MM
E E
Maximum from MB and MZ (Time-Based Maintenance)
It’s important for you to understand the key difference between CTM planning and other planning tools in SAP APO for the SS methods SM and MM. For CTM planning using the SM and MM methods, both the SS and SDS values are used instead of the maximum of the SS and SDS.
For the constant safety stock (SS) and Safety Days of Supply (SDS) methods (SB, SZ, SM), the SS values are maintained in the product master using the Safety Stock and the Safety Days Supply fi elds under the Lot Size tab of the product master. The SS value is maintained in the base unit of measure (UOM) of the product. SDS is maintained as the number of days and must be maintained in multiples of days.
The SS methods that are available in CTM planning are shown in Table 5.1.
Safety Stock Methods Constant Time-Phased
Safety Stock SB MB
Safety Days of Supply SZ MZ
Both SS and SDS SM MM
Safety Stock Methods Available in CTM Planning Table 5.1
When planning with SS methods MB, MZ, and MM, time-phased SS and SDS val-ues can be maintained for CTM planning using the time series key fi gure of the SNP planning area (see Figure 5.2).
The SNP key fi gure used for maintaining the time-phased values must be made available for CTM planning using the customization Make SNP Key Figure Avail-able as shown in Figure 5.3. The customization setting can be accessed using IMG
• Advanced Planning and Optimization • Supply Chain Planning • Multilevel Supply and Demand Matching • Capable To Match • Make SNP Key Figure Available.
The key fi gure functions 11 and 12 are available to defi ne the key fi gure used for SS and SDS. The planning object 9AMALO must be used for the SNP planning area that you want to use for CTM planning. If you maintain multiple key fi gures for the same function, then CTM will use the fi rst key fi gure for time-phased data selection. The planning area that can be used for CTM planning can be defi ned in the CTM global customization under the ATP Categories tab. It’s also possible to defi ne a CTM profi le-specifi c planning area under the Technical Settings tab of the CTM profi le. In this case, CTM the profi le-specifi c planning area is used for key fi gure selection before using the planning area maintained in the CTM global customization.
Make SNP Key Figure Available for CTM Figure 5.3
When using the SNP time series key fi gure, the key fi gure values are selected based on the storage bucket profi le of the planning area. The time bucket profi le used in the planning view isn’t used for data selection. If you plan to use time buckets that are different from the storage buckets, you must use the No Disaggregation function for the key fi gure to ensure that the SS and SDS values are selected for CTM planning with the appropriate time buckets.
Using the CTM master data check function, you can validate the time-phased key fi gure values used for CTM planning as shown in Figure 5.4. This is a very use-ful function where you can check whether all of the appropriate customization is made to make the SNP key fi gure values available for CTM planning.
CTM Master Data Check for Time-Phased Safety Stock Values Figure 5.4
After you’ve made the appropriate selection of the SS planning methods and the relevant SS and SDS values, the CTM planning run will generate the supply plan to fulfi ll SS and SDS. In the next sections, we’ll take a detailed look at planning for SS and SDS in CTM.