How to Understand SAP Supply Network Planning
Executive Summary
- SNP is APO’s module that deals with supply planning and SNP has an important impact on SAP DP forecasting.
- Where the SNP sequence fits into the demand, supply, and production planning process.
Introduction
SNP is the supply planning module in APO. This article will learn about SNP’s major configuration areas and the different things that SNP does.
The Relationship Between SNP and Other Modules and ERP
- SNP or Supply Network Planning takes a look at requirements, typically although not necessarily from DP.
- It compares the demand plan to calculated projected on-hand (and can incorporate capacity through either SNP PPMs and PDSs or through connecting to PPDS) to determine the allocation of requirements to both stock and production.
- The overall supply chain network is set up by creating transportation lanes imported from SAP ERP from scheduling agreements described in this article.
SNP’s Impact on DP and the Forecast
One of the big questions with regards to SNP is how it consumes the forecast. We quote from SAP SNP 230 training material on this topic.
“Depending upon which strategy you choose, sales orders can affect demand, consume planned independent requirements or have no effect on demand.”
As for the types of planning approaches SNP supports, it supports make to stock only. This includes SAP ERP make to stock production, planning with final assembly, and subassembly planning.
Where The SNP Sequence Fits into a Demand, Supply, and Production Planning Process
There are some sequences possible with SNP. Here is one:
- Perform SNP Run
- Review Problems
- Release feasible SNP plan to DP
- Complete PPDS Run
- Run Deployment
- Run TLB
The SNP Planning Results
We quote from SAP Supply Network Planning 230 training material again to describe what can happen with the SNP plan:
The final SNP plan consists of feasible purchase reqs, SNP stock transfers and SNP planned orders. You can convert SNP planned orders into PPDS planned orders in the production horizon using the PPDS planning run. The planned independent requirements and SNP sotck transfers are covered by PPDS planned orders. The final SNP or PPDS plan can be released to DP again to compare the unconstrained demand plan with the feasible procurement plan. If the two do not match, you can use a macro to trigger alters to that the demand planner can plan the foreasts again.
The Major Areas
Here are some of the major configuration areas with SNP IMG.
The Planning Books
Many different views are different planning books. This includes:
- Interactive Supply Network Planning: This is the major planning book and is used in the standard workflow.
- Sales and Operations Planning: This is not used very much as a view, and it is, in a way, misnamed. SOP involves sharing information between sales and operations, and finance. However, a planning book cannot do this because it is primarily a tool of operations. There was, at one time, a product called SEM. However, this product has died in the marketplace. The best way we know of to support SOP is with extracts from the SCM system.
- Collaborative Supply Planning: This opens up a web page and allows partners to enter values that persist in SNP.
The SNP Environment
The IMG environment area allows some housekeeping functions to be auctioned. This includes forecast generation, release to demand planning, mass maintenance of time series key figures, forecast to demand, and process chain maintenance.
Planning in The Background
This allows many of the Supply Network Planning functionalities to be set in the IMG to be run in the background.
SNP Basic Settings
Data warehousing workbench is one part of the area to configure in the IMG under basic settings. But there is much more under this configuration category—macros, planning bucket profiles, etc.
SNP Profiles
This may be the most important part of the Supply Network Planning IMG configuration. Lot size profiles can be created, which allows them to be assigned very flexibly. Cost profiles are used in normal optimization and deployment optimization. There is also the ability to created optimization profiles. Once the heuristics have been implemented, it is important to have capacity leveling profiles.
CTM Setup
CTM IMG configuration includes setting up the supply categories, demand prioritization, and search strategies. These are all then included in the CTM profiles.
The Methods in SNP
SNP can be run in three ways. These methods are listed from easiest but least optimal to most challenging and most optimal:
If constraints are used in SNP or through PPDS, capacity leveling is unnecessary, but if not, capacity leveling will need to be done. Capacity leveling in SNP is described in this link.
Stock Transfers
In addition to planning consumption from planned location stock, SNP can also initiate repositioning or eventually become a Stock Transport Order in SAP ERP.
Safety Stock Planning
Supply Network Planning has extensive functionality in safety stock planning with static, dynamic, and service level-based methods available to the configuration team.
Lot Sizing
An imperative control for how Supply Network Planning orders are the lot size setting on the product master. If the lot sizing is not correct, the Supply Network Planning plan will bear higher costs than necessary. However, Supply Network Planning provides both a simple and powerful lost sizing control panel on the product master, fully explained at this link.
Supply Network Planning Deployment
How inventory is moved to competing locations in the case of over and undersupply is called deployment. The functionality to deployment is similar to the functionality for initial planning and is described at this link.
Supply Network Planning Standard Planning Books
Just a quick listing of all the Supply Network Planning standard planning books that ship with SCM. Of course, you can create any number of custom planning books from scratch, make a copy of the planning books below, change them, and then save them as a new planning book.
Planning Books
- 9ASNP94 for traditional Supply Network Planning
- 9ASOP for Sales & Operations Planning (SOP)
- 9ADRP for Distribution Resource Planning (DRP)
- 9AVMI for Vendor-Managed Inventory
- 9ASA for scheduling agreement processing
- 9ASNPAGGR for aggregated planning and planning with aggregated resources
- 9ASNP_PS for planning that takes into account product interchangeability
- 9ATSOPT for optimization-based planning that takes into account time-based constraints
- 9ASNP_SSP for safety stock planning
- 9ADRP_FSS for planning with the deployment heuristic with consideration of demands in the source location)
What Are SNP Global Settings?
They define at the highest level how Supply Network Planning deals with its environment. Some settings range from when messages should be created to how blocks should be calculated to the product unit in the location master. Many settings control how the procedures that are available in the SNP process location product combinations.
For instance, backward and forward scheduling is set up for CTM on the CTM Profile. However, for the SNP Heuristic, this setting is not maintained on the SNP Heuristic screen. Instead, this setting is kept in the SNP Global Settings.
Understanding the SNP Global Settings
The best way to learn what controls are available is to move through the list. During the blueprint meetings on the project, the objective is to figure out which should be changed from their default values.
They can be found in the IMG underneath SNP -> Basic Settings -> Maintain Global SNP Settings.
The Global Supply Network Planning Settings Screen
There are so many interesting settings in this area. Some of these are the following:
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- Whether to transfer planned (production) orders from R/3 for the entire planning horizon or just the production horizon.
- Whether product interchangeability should be activated.
- Whether to use GR processing time for planned orders.
- Where the lot size profile should come from (the Tlane, the destination location product, or ignore all lot sizes)
- Whether the TLB lot size should be the rounding value of the Tlane or the rounding value of the destination location product)
- Backward scheduling, or the “first possible date,” which is a much more accurately defined term of what is also called forward scheduling.
- Whether to allow direct delivery.