COBOL code review checklist

Data

• Are numeric fields validated before arithmetic?
• Could any MOVE truncate silently? Is ON SIZE ERROR needed?
• Are working-storage fields initialised on every path, especially in called programs?
• Do table loads check the OCCURS bound?
• Do REDEFINES reinterpret data safely?

Logic

• Are scope terminators used instead of relying on full stops?
• Are conditions expressed as 88-levels where it helps readability?
• Is every EVALUATE covered by WHEN OTHER?
• Are paragraphs performed rather than fallen through?

I/O and errors

• Is FILE STATUS checked after every operation?
• Is every SQLCODE handled, including +100?
• Is the error path informative — program, paragraph, key, and the message text?
• Does the program set a meaningful RETURN-CODE?

Operations

• Does it print record counts?
• Does it display the current key periodically, so a failure can be located?
• If it updates, is it restartable? Is there a checkpoint?
• Is the commit frequency a parameter rather than a constant?