Consistency Check in the Budget Control System
Use
You use this function to define checks in the budget control system (BCS) which are always run before a budget value can be saved in the database. If you are also using the integrated BCS
Planning Tool, the consistency check also takes place when you enter plan data.The consistency checks you activated are run in the background when you post or prepost a budget amount. A consistency check is not automatically carried out for held documents. However, you can run a consistency check for held entry documents by pressing the 
(Check Document F7) pushbutton in the budgeting workbench.
If you use the budget control system as an operative budgeting tool in Funds Management, then consistency checks are not activated by default. You define and activate checks according to customer-specific perspectives in the check rules. One or more check rules are managed in a check library. If a check rule is not complied with in the consistency check, you can define the corresponding system reaction via message control and thereby issue a system message to the user.
The Negative Budget indicator in BCS in the master record of commitment items is not considered. If you want to prevent negative budget being posted in your organization, you must define this in a check rule.
Prerequisites
Key figures and customer-defined messages are used in the consistency check. You must have created both before defining the check rules:
Features
Check libraries
Consistency checks are managed in check libraries. Check libraries can be used in different FM areas/fiscal years and versions. You define the valid currency for each check library. For example, you work in an international organization and can copy the check libraries already defined and change the currency to match the respective FM area.
Structure of a check rule
In a check rule, you select which account assignment element should be evaluated in the check rule by using an aggregation of the non-relevant FM account assignment element.
You define one or more check rules for each check library which are run one after the other. A check rule consists of three sections:
In the prerequisites section, you define the selection of budget postings by using a formula which undergoes this check rule.
This section includes the actual consistency check. By using key figures or fixed values, you define a formula that a budget posting must fulfil in order to be consistent. Tolerance values can also be considered. If an inconsistency occurs, the corresponding system reaction that you defined in the Message section is issued. If the consistency check is successful, the following check rules are run. Only when all checks have been successfully competed is the budget amount saved in the database.
In this section you define the system reaction for when a consistency check finds an error. Depending on the definable message class, budget postings can be prevented and warning/success messages issued. You can specify the issued messages using message variants. SAP delivers predefined message variants for this.
Check for each budget entry document or for each budget address
In the BCS consistency check, checks either include only the amounts in the entry document to be posted and checks whereby the amounts in the entry document to be posted are compared with those budget amounts in the database already posted. Check libraries that are used to check budget entry documents or budget addresses are also distinguished accordingly. Note that budget account assignment-specific consistency checks affect system performance.
Activities
You define these check rules in the Customizing of Funds Management, under Budget Control System (BCS) ® BCS Budgeting ® Consistency Check.
For more information, see the Implementation Guide.