How to perform expert sizing for SAP BPC NW (Part 1 - Basic Steps and Approach)

[Former Member]

I have been involved with multiple sizing engagements for customers and several large SAP BPC projects, one of the things that always struck me was the perception regarding sizing or the lack of information regarding these exercises. There seems to be some confusion on how custom or expert sizing is performed and how the sizing is determined or the process thereof in determining the sizing.

This blog will hopefully shed some light on how to perform expert sizing.

Please Note: It is the intention of this blog to explore the methodology regarding how to perform sizing and to provide some real world examples on how perform expert sizing which was done on past implementations. It is important to understand the process, but also to realize that in large implementations, there is always a need to engage with SAP on expert sizing. Due to the nature of large project implementations sizing becomes a critical factor for the successful implementation of a solution. This blog is meant to provide and overview of the sizing process, but doesn't replace the need for expert sizing, there are several factors that need to be taken into account that this blog unfortunately doesn't' cover..

It is assumed that the reader has read the sizing guidelines for SAP BPC NW, this blog will make reference to these guides. These guides contain essential information which is required for expert sizing. It is highly recommended to always refer to the latest version of the sizing guidelines.

Reference Link: SAP BPC NW Sizing Guidelines

High Level Overview of the sizing methodology

Step 1 - Some basics and foundation information

First and foremost, you need to know what you are sizing and for which platform?. In addition there is also some basics that you need to take into account, For example: What phase in the project are you in, What are some of the non functional requirements and some of the environmental influencing factors.

Some of the major non functional factors that need to be taken into account are:

• Is this a shared solution ? : (For Example: Are you deploying SAP BPC NW on a shared BW system landscape, or a standalone isolated SAP BPC NW system landscape. This becomes more a TCO and Architectural discussion, but when performing sizing it is important to understand the constraints that you are deploying SAP BPC in)
  • If it is a shared SAP BW landscape, has SAP BW been sized correctly?, has the anticipated SAP BW usage been taken into account ?, At what point does it make sense to separate SAP BPC from the shared SAP BW landscape. Although some of these questions are subject to greater discussions and subject to architecture, project, organizational principles and governance, you will need to take them into consideration for your sizing exercise.

• BW Platform : (What platform are you sizing for, this depends on the platform, there is different sizing requirements and formulas for the different platforms. [Classic BPC NW, this scenario is when SAP BW is on a classic RDBMS such as ORACLE, IBM DB2, MSSQL, etc. BPC on HANA, this scenario is when the SAP BW database platform is using SAP HANA as its database platform])

Step 2 - Get some basic metrics and information

In order to perform sizing, there is some basic and important information that is needed, without it; any form of sizing will not be possible:

The sizing guideline will provide a complete list of information that you will need. Typically this information will be provided by the respective functional teams or solution architect.

It is also very important to understand your user community, as this will tell you how your SAP BPC NW solution will be implemented through out the business. i.e: How many super users, how many input capture(s), etc. Based on past experience, I find it easier to categorize the user community and based on the number of the users in the categories you can determine the basic tasks and activities within SAP BPC,

For Example:

• Expert users - These are typically the users who are classified as 'Super Users'. These users in your SAP BPC user community normally have the most expert knowledge on SAP BPC. These users are typically the 'go to' users for your SAP BPC community and normally have the most intimate knowledge of the implementation environments and landscape. If you have a large number of expert users, then you will need to take into account, that some of these users will be writing there own script logic, processing dimensions, changing business rules, adding, changing, deleting business process flows, etc
• Business Users - This user base, will form the majority on your SAP BPC user community, these users will probably use a combination of the EPM Add-In and web interface, along with SAP BusinessObjects reports. These users will typically be responsible for the process flows, data capturing, data modification,etc
• Information Consumers - This user community is typically a smaller number of users, due to the fact that they would only really refresh reports, submit data via Input Schedules, etc

Once you have an understanding of the user community and anticipated usage of the SAP BPC solution, it will be easier to understand the anticipated workload of the system. In addition to the above information some very critical information that you will also need is :

• # Number of users
• # Number of environments
• Master Data integration and data architecture
• Complexity of Application(s), Business Processes and Calculations
• Data Architecture, Reporting Architecture( Are you going to be using SAP BusinessObjects Business Intelligence Platform for your reporting, Dashboards, etc)
• Anticipated usage of application, i.e. Are the majority of your users going to be using the EPM Add-In exclusively, the web front end, What is the % of users going to be using BPF's, how complex are the BPF's going to be...

Step 3 - Perform delta sizing from T-Shirt Sizing

Once you have some basic metrics and information regarding the SAP BPC environments and applications, you can start to get an idea of the baseline category that your sizing will be. There are baseline T-Shirt sizing categories per the sizing guides, they offer a indicative baseline that will be a base for the sizing exercise.

Its important to understand that the baseline sizing categories provide you with a estimated and baseline number of SAPS, based on the information provided by the respective functional teams you will be able to get an understanding of how much different your implementation will be.

Step 4 - Expert Sizing and determine the delta SAPS 

Once you have determined your baseline SAPS, your use the formula's outlined in the sizing guides to determine the delta SAPS and this will determine the anticipated number of SAPS required for your implementation. Although most of the steps outlined are pretty self explanatory and are in the SAP Sizing guidelines for the respective SAP BPC NW solutions, in Part 2, using some real world examples, some of this information will start to make more sense. 

Sizing Approach for the respective environments

The below graphic provides a visual representation of the sizing approach and methodology: This graphic is from a real world sizing exercise and shows the the approach taken for the respective environments.

Some Key Take away(s)

• Sizing is based on inputs...  so the most basic principle applies ..[ Garbage in, Garbage Out ...]

What ever your Functional teams, Solution Architect, project manger tell you, the values that they input, will have a direct and corresponding value on the sizing. For Example: If your functional team leads says that your SAP BPC solution will be deployed to 1400 users, then you have to size according to 1400 users, this has a direct financial cost, because you will need a system that can handle 1400 users, etc

• Understand your SAP BPC community

The more you understand your SAP BPC user community, the easier it becomes to manage and understand your workload. Different activities within SAP BPC have different behaviors on the system. The more you understand your community, the easier it becomes to mitigate and manage.

• Sizing is a small but very critical portion of the project.

Understand that there are other factors that drive the adoption, deployment and ultimately the success of the SAP BPC solution.

• Expert sizing should provide you with a comfort factor of about 70 -80 % on your platform and environment.

Performance testing should provide you with clarity on if you've over sized, undersized your environment. Ultimately, performance testing should identify the sweet spot on your environment and solution landscape.

• Sizing is an iterative exercise

Its very important to understand that sizing is an iterative approach and that once you've performed expert sizing, it doesn't mean that your done and dusted. As with every solution and implementation. It is very important to realize that expert sizing should provide you with a comfort level of 70-80% on what your landscape and environment should be, but performance testing will verify and provide the opportunity to find that sweet spot of your environment. For Example: You've undersized or over sized, etc.

In Part 2 of this blog series, I will provide a real life example of an expert sizing exercise for a large SAP BPC implementation