The common work area (CWA)

The common work area (CWA) is an area of storage in your CICS® region that any user application can access. You determine the size of this work area by using the WRKAREA system initialization parameter; you can specify sizes up to 3584 bytes.

If you omit the WRKAREA parameter, CICS allocates a 512-byte CWA by default. You specify the storage key for the CWA on the CWAKEY parameter.

This work area is available to all transactions in a CICS region, so you must ensure that the storage key is appropriate to the use of the CWA by all transactions. If any of the transactions run in user key and require write access, you must specify user-key storage for the CWA, otherwise such transactions fail with a storage protection exception (an ASRA abend). CICS obtains user-key storage for the CWA by default, and you must review the use of this storage by all programs before you decide to change it to CICS-key storage.

It is possible that you might want to protect the CWA from being overwritten by applications that should not have write access. In this case, provided all the applications that legitimately require write access to the CWA run in CICS key, you can specify CICS-key storage for the CWA.