How you can lower down your support costs for SAP validations and substitutions. And ease your own life.

Dmitry Kaglik

November 25, 2012



SAP Validations
SAP Validations

Substitutions and validations are an inevitable part of a SAP project. You always need to chec

k that the document is entered correctly, or replace values in certain fields.
SAP allows you to write subs and vals in an easy-to-use interface similar to the constructor. A few mouse clicks, a few keystrokes and you’re sorted.
But how often do you need to amend validations or substitutions back and forth to allow something restricted to happen? Often? Then probably we need to look at the way your subs and vals are coded.
Say your validation is about tax codes which you created after the tax rate change. It says

  • Prerequisite: BKPF-BLART = ‘KR’ OR BKPF-BLART = ‘RE’
  • Validation: NOT ( BSEG-MWSKZ = ‘V1’ OR BSEG-MWSKZ = ‘V2’ OR BSEG-MWSKZ = ‘V3’ )
  • Message: “Please do not use old tax codes”

Obviously, V1, V2 and V3 are old tax codes which you should not use after the tax switch date.
But now and then an odd invoice comes for services which were provided when the old tax rate was in use. It should be posted with one of the old tax codes. What do you do in this case? You need to create another transport, change validation and move the new validation across the systems’ landscape to the Production system. Then you need to do same process again to put the restrictions back.
Is it possible to optimize the process and simplify both the support process and your own life?
SAP allows you to use sets in validations. The benefit of using sets is that they can be changed directly in the Production system without any transports.
First, you need to create sets in Development: transaction code GS01 helps you here.
Second, you use sets in your validations. For the example above, you can rewrite the validation like this:

  • Prerequisite: BKPF-BLART IN Z_SET_OF_BLART
  • Message: “Please do not use old tax codes”

Third, you move your validation across to Production. Once only!
Then you only need to maintain sets in the transaction code GS02 if restrictions are to be temporary lifted, or more document types or tax codes added.

Easy? Yes!

Quick? Yes!

Clear? Surely yes!

Related Posts

What is the place of OpenSAP in SAP education landscape?

Dmitry Kaglik

August 5, 2019


No Comment

FacebookTwitterLinkedinDiggemailSAP is a company that develops and sales many software applications. Of course, the most well-known of them is SAP R/3, also known as SAP ERP, SAP ECC and now SAP S/4HANA. There are also other products like HANA, SCM, CRM, Concur, Successfactor and so on. Each of these products is very complex. It is […]

Read More

Payments with Payment Requests and Repetitive Codes

FacebookTwitterLinkedinDiggemail Introduction Payments in SAP is a very important topic. Most often these are payments made to vendors. There are multiple ways how you can pay vendors in SAP using invoices or down payment requests. Some special cases require you to make payments without an invoice, and Payment Requests become handy in these cases. If […]

Read More


  • Michele on February 20, 2013

    I would like to know why the MWSKZ is deactivated for sap standard for the substitutions. We have to go and reactivate it, but is this best practice?

    • Dmitry Kaglik on February 20, 2013

      Hello Michele,
      The system that I have access to, includes the field MWSKZ in the list of availble for substitution, even though we’ve never subsstituted it.
      My other projects did include tax code substitution, and I don’t remember me making this field available.
      So, maybe this is something very specific in your system(s)?

  • Arkoni on February 6, 2014

    I habe a case where i need to use validation. How can I create validation of the two first letters invoice number?

    • Dmitry Kaglik on February 6, 2014

      Validation maintenance is in transaction OB28 and GGB0.
      There is a constructor available for easy building the validation rules. If you want additional SAP Expert’s assistance, please contact for help.

Leave a Reply

Your email address will not be published. Required fields are marked *

Search this site


You can subscribe to our regular updates here.


Will you be happy to pay for the 3rd edition of the book FREQUENTLY ASKED QUESTIONS ON SAP FINANCE?

View Results

Loading ... Loading ...
Disclaimer and privacy policy