Legacy systems have been tuned and streamlined over many years, and they most likely perform very well. Leveraging these existing assets in place, where possible, is the best approach to capitalizing on the investment and years of work spent perfecting them.

An information silo is a management system incapable of shared operations with other, related management systems. A bank's management system, for example, is considered a silo if it cannot exchange information with other related systems within its own organization, or with the management systems of its customers, vendors, or business partners. "Information silo" is a derogatory expression that is useful for describing this type of relationship. 

The silo effect is a phrase that is currently popular in the business and organizational communities to describe a lack of communication and common goals between departments in an organization. It is the opposite of systems thinking in an organization. The silo effect gets its name from the farm storage silo, probably because there could be five silos right next to each other and if people were inside them they would not be able to communicate, since silos are tall, narrow buildings with no windows and are even supposed to be airtight.[WIKIPEDIA] http://en.wikipedia.org/wiki/Information_silo

 

Request our white paper on silos and RIPPLE-TRAC™.

See how a RIPPLE-TRAC™ session might work below.

We requested an impact on field ‘VARIABLE-START-POS’. We wish to change the size of this field. As you can see below, this field was found in module ZRULES seven times. Once in WORKING STORAGE (WS) and 6 times in the PROCEDURE DIVISION. (P)

 

 

 

MODULE	TYPE	PROJECT	BACKREF	COMPONENT NAME	COMPONENT	DESCRIPTION
ZRULES	C			COPY	XDCOMNC
ZRULES	F			(WS)	VARIABLE-START-POS	OFFSET NUMBER
ZRULES	C			COPY	XDLMID2C
ZRULES	C			COPY	XDLMIDC2
ZRULES	C			COPY	XS2034W
ZRULES			&XS2034W	..NO COMPONENTS	­
ZRULES	C			COPY	XS3300W
ZRULES			&XS3300W	..NO COMPONENTS
ZRULES	C			COPY	XS3300R
ZRULES			&XS3300R	..NO COMPONENTS
ZRULES	C			COPY	XSSTATE
ZRULES			&XSSTATE	..NO COMPONENTS
ZRULES	C			COPY(P)	XS2034P
ZRULES			&XS2034P	..NO COMPONENTS
ZRULES	C			COPY(P)	XS3300P3
ZRULES			&XS3300P3	..STATIC CALL	XD2137
ZRULES	F			(P)	VARIABLE-START-POS	OFFSET NUMBER
ZRULES	F			(P)	VARIABLE-START-POS	OFFSET NUMBER
ZRULES	F			(P)	VARIABLE-START-POS	OFFSET NUMBER
ZRULES	F			(P)	VARIABLE-START-POS	OFFSET NUMBER
ZRULES	F			(P)	VARIABLE-START-POS	OFFSET NUMBER
ZRULES	F			(P)	VARIABLE-START-POS	OFFSET NUMBER
ZRULES			&XS3300P3	..STATIC CALL	XD2137
ZRULES			&XS3300P3	..STATIC CALL	XD2137
ZRULES			&XS3300P3	..STATIC CALL	ILBOABN0	force an abend and obtain a system dump.

 

Now we will map ‘VARIABLE-START-POS’ to where it is used in the ZRULES module and extract the business Rule. (Done manually in this release)

 
The routine that ‘VARIABLE-START-POS’ is used in:

 

7000-020-LOOP-SOURCE.

      * ......setup for space check before and after data....

           MOVE START-POS TO VARIABLE-START-POS.

           SUBTRACT +1 FROM VARIABLE-START-POS.

           COMPUTE VARIABLE-END-POS =

                   VARIABLE-START-POS + LENGTH-OF-LABEL + 1.

           IF SOURCE-DATA(START-POS:LENGTH-OF-LABEL)

             = ARG-LABEL(AT1-SUB), (1:LENGTH-OF-LABEL)

             AND SOURCE-DATA(VARIABLE-START-POS:1) = '.'

             MOVE SPACE TO SOURCE-DATA(VARIABLE-START-POS:1)

           END-IF

           IF SOURCE-DATA(START-POS:LENGTH-OF-LABEL)

             = ARG-LABEL(AT1-SUB), (1:LENGTH-OF-LABEL)

             AND SOURCE-DATA(VARIABLE-START-POS:1) = SPACES

             AND SOURCE-DATA(VARIABLE-END-POS:1)   = SPACES

             MOVE SOURCE-NAME TO IMP-MODULE-NAME

             MOVE SOURCE-DATA(START-POS:LENGTH-OF-LABEL)

               TO IMP-MODULE-COMP, GENERIC-DESC-HOLD-AREA

             MOVE ARG-PROJECT(AT1-SUB) TO IMP-MODULE-PROJECT

             MOVE ARG-TYPE(AT1-SUB) TO IMP-MODULE-TYPE

             PERFORM  VARYING TT-SUB FROM +1 BY +1

                   UNTIL TT-SUB > GENERIC-DESC-VIRTUAL-AT-END

                IF GENERIC-DESC-NAME(TT-SUB)

                                  = GENERIC-DESC-HOLD-AREA

                  MOVE GENERIC-DESC-DESC(TT-SUB)

                    TO IMP-MODULE-COMP-DESC

                  PERFORM 7000-030-CHECK-ON-MODEL

                     THRU 7000-030-EXIT

                END-IF

             END-PERFORM

             PERFORM 9000-EDIT-IMP THRU 9000-EXIT

             ADD +1 TO HIT-COUNT

             WRITE IMP-RECORD

             MOVE SPACES TO IMP-RECORD

             ADD +1 TO START-POS

      *      MOVE 'F' TO FOUND-SW

      *      MOVE +72 TO START-POS

           ELSE

             ADD +1 TO START-POS.

       7000-020-EXIT. EXIT.

This routine is fairly complicated, so we will flowchart it. But first let’s look at the complexity metrics.

 

COMPLEXITY METRICS

The following metrics measure the complexity of executable code within procedures. This includes both the internal complexity of a single procedure and the complexity of the data flow in and out of a procedure.

High complexity may result in bad understandability and more errors. Complex procedures also need more time to develop and test. Therefore, excessive complexity should be avoided. Too complex procedures should be simplified by rewriting or splitting into several procedures.

Complexity is often positively correlated to code size. A big program or function is likely to be complex as well. These are not equal, however. A procedure with relatively few lines of code might be far more complex than a long one.

 

VALUES OF CYCLOMATIC COMPLEXITY

A high cyclomatic complexity denotes a complex procedure that's hard to understand, test and maintain. There's a relationship between cyclomatic complexity and the "risk" in a procedure.

CC	Type of procedure	Risk
1-4	A simple procedure	Low
5-10	A well structured and stable procedure	Low
11-20	A more complex procedure	Moderate
21-50	A complex procedure, alarming	High
>50	An error-prone, extremely troublesome, untestable procedure	Very high

The original, usual limit for a maximum acceptable value for cyclomatic complexity is 10. Other values, such as 15 or 20, have also been suggested. Regardless of the exact limit, if cyclomatic complexity exceeds 20, you should consider it alarming. Procedures with a high cyclomatic complexity should be simplified or split into several smaller procedures.

Cyclomatic complexity equals the minimum number of test cases you must execute to cover every possible execution path through your procedure. This is important information for testing. Carefully test procedures with the highest cyclomatic complexity values.

Bad fix probability

There is a frequently quoted table of "bad fix probability" values by cyclomatic complexity. This is the probability of an error accidentally inserted into a program while trying to fix a previous error.

CC	Bad fix probability
1-10	5%
20-30	20%
>50	40%
approaching 100	60%

As the complexity reaches high values, changes in the program are likely to produce new errors.

As you can see, this routine received a 5 on the complexity scale.

See additional info at en.wikipedia.org/wiki/Cyclomatic_complexity

Automatically flowchart the code:

Forward engineer the flowchart into VISIO.

 

 The business rule is now ready to include into the use case.