Understanding COND=(0,NE) in JCL

 The COND parameter is often one of the most confusing JCL concepts for beginners because its logic works in a somewhat counterintuitive way.

When you code COND=(0,NE) on a job step, the condition is evaluated against the return codes of all previous steps.

• If any previous step returns a code other than 0, the condition (0,NE) evaluates to true, and the current step is bypassed (FLUSHED).
• If all previous steps return 0, the condition evaluates to false, and the current step executes normally.

 In simple terms, COND=(0,NE) means "Execute this step only if all preceding steps completed successfully with RC=0."

Example

//STEP1    EXEC PGM=IDCAMS
//SYSPRINT DD SYSOUT=
//SYSIN    DD
  SET MAXCC=4
//*
//STEP2    EXEC PGM=IEFBR14
//*
//STEP3    EXEC PGM=IEFBR14,COND=(0,NE)
//*

Execution Results :

Step Name	Return Code
STEP1	04
STEP2	00
STEP3	FLUSH

 

Why Was STEP3 Flushed?

 

• STEP1 ended with RC=04.
• Since 04 is not equal to 0, the condition COND=(0,NE) becomes true.
• As a result, STEP3 is skipped (FLUSHED).

 

Even though STEP2 completed with RC=00, JCL evaluates the condition against all preceding steps, not just the immediately prior step. Because STEP1 returned a non-zero code, STEP3 does not execute.

 

Key takeaway: COND=(0,NE) is commonly used to ensure a step runs only when all earlier steps have completed successfully with a return code of zero.