The Location Versus the Network Heuristic in SAP

ByShaun Snapp

Table of Contents: Select a Link to be Taken to That Section

Executive Summary

  • The SNP network heuristic is used for the initial supply plan.
  • There are different flavors of running the network heuristic with either the location heuristic or the network heuristic.
  • This highlights the need to consider how the supply planning problem is divided or decomposed by different methods.

Introduction

The SNP Heuristic is one of the three ways to perform supply planning in SNP, the others being optimization and CTM. The SNP Heuristic is often referred to as just that, yet, in fact, the SNP Heuristic can be run in two different ways. This is evident from the settings where the SNP Heuristic is run in the background.

Network Heuristic

There are quite a few options on the SNP Heuristic options screen. One of the most important settings is whether the Network or Location Heuristic will be run. I take the following quotation from SAP Help. 

  1. If you select Network, the system plans the specified products in all the supply chain model locations where these products are reassigned.
  2. If you choose Location, the system plans the specified products in the specified locations. This allows you to select the part of the model to be planned. 

This setting interoperates with other settings in this options screen. Both the Network and Location Heuristic had different ways of dividing up the supply planning problem. Dividing a problem is referred to as decomposition and is covered in detail at this link. Decomposition is a primary way of differentiating supply planning methods from one another and even creating different “flavors” within each of the methods – the Location versus the Network Heuristic is a perfect example of this.

The Location Heuristic

When the Location Heuristic is used, the Heuristic processes the supply network problem by Location. Therefore, if this selection is made, it is necessary to declare which Locations are in the planning run.

Using a Location Heuristic and grouping of Locations is possible. That provides a great deal of Location control. The Locations can either be added to this options screen, or they can be entered in the Selection Profile. That is, the Selection Profile can declare the combinations to be processed.

This has the advantage of allowing planners (the business) to move Products and Locations in and out of various Selection Profiles, as the Planning Books control the Selection Profiles. Rather than placing the Product and Locations into the background transaction, the planners may not have access to or may not be familiar with.

The Network Heuristic

When the Network Heuristic is used, all control over the locations that are part of the planning run is lost. In fact, if you select the Network Heuristic option, the Location field grays out and is no longer an option (as does the Low-Level Code field). The Heuristic will process all Locations or the entire “network.” This phrase is used quite often, but the full implications are not understood.

The Network Heuristic is called what it is for an apparent reason. However, to make both approaches to running the Heuristic more intuitive, one might call the Location Heuristic the Sub-Network Heuristic, while calling the Network Heuristic the Total or Complete Network Heuristic. Or instead, there could have been a dialog button that allowed the user to switch between running all Locations or specific Locations. Both of these changes would make the SNP Heuristic more understandable.

Exception

While I have laid out the official reasons for using either the Location Heuristic or the Network Heuristic, it is a bit more complicated because of bugs in APO. For instance, the Network Heuristic has problems when subcontracting is being used.

Subcontracting is one of those areas of functionality that was not thoroughly tested with other APO functionality, so subcontracting in APO when it can be made to work — tends to cause problems in multiple areas. However, the Location Heuristic does work with subcontracting. Therefore a solution or workaround that has been used by companies that have SNP and do subcontract is to run the Location Heuristic but run it for all Locations.