Problem:

Numeric value not recognized in a Signed field during a compare statement

For example

01 WS-VAR.
     03 WS-ZERO-X    PIC X(3).
     03 WS-ZERO REDEFINES WS-ZERO-X   PIC S9(3).
     03 WS-NUMERIC         PIC S9(3).
 
Procedure Division.

MOVE '000' to WS-ZERO-X
MOVE WS-ZERO to WS-NUMERIC.

IF WS-NUMERIC NOT = 0
.....
ELSE
.....
END-IF.

Where the IF statement is executed instead of the ELSE statement.

Resolution:

Compile programs using the directives SIGN-FIXUP and HOST-NUMCOMPARE.

SIGN-FIXUP provides a limited emulation of the mainframe compiler option NUMPROC(NOPFD) when using the HOST-NUMCOMPARE and HOST-NUMMOVE directives.