Rule Definition
Parts of data can be accessed by using their position and their length in a data group. This mechanism is error prone for two points: the developer can introduce errors in defining the position of the part of data to access. In addition, this position is dependent of any changes in the data before placed before it. Thus, problems can easily occur in production and data may be corrupted.

Remediation
Data which need to be accessed partially must have detailed fields. Then, look for accesses using position and length and replace them by fields accesses.

Violation Code Sample

01 WSS-RUB     PIC X(10).
01 WSS-VAL     PIC X(20).
01 WSS-ENTITY PIC X(8).
...
IF WSS-RUB(1:3) = 'BAK' 
    MOVE WSS-VAL (1:8) TO WSS-ENTITE
END-IF

Fixed Code Sample

01 WSS-RUB.
    05 WSS-RUB-ID PIC X(3).
    05 FILLER           PIC X(7).
01 WSS-VAL.
    05 WSS-VAL-ENTITY    PIC X(8).
    05 WSS-OTHER-DATA PIC X(12).
01 WSS-ENTITY PIC X(8).
...
IF WSS-RUB-ID = 'BAK' 
    MOVE WSS-VAL-ENTITY TO WSS-ENTITE
END-IF