defining change control severity

Greetings everyone,

We are currently trying to come to a working definition of 'major' versus
'minor' change in our development process. At present we have a weighted
scale that factors in the Type, Impact and Degree of Difficulty of the
change, as indicated below:

Type of Change  
 Version Upgrade (new system)   A
 Functional Enhancement                 B
 Bug Fix / Error Correction             C
        
Impact of Change        
 Direct Financial Statement Impact      A
 Direct Customer Function Impact        B
 Behind the scenes                      C
        
Degree of Difficulty of Change  
 Major Complexities                     A
 Minor Complexities                     B
 Straight Forward - nothing complex     C
        
If there is an "A" in any of the three categories, it is deemed a major
change. A response of all "B" is likewise deemed major; everything else is
minor.

This is rudimentary at best and still involves judgment calls by
individuals, something we'd like to keep to a minimum. If anyone has
suggestions based on their own work in this regard or can provide links to
useful reference material, I'd appreciate hearing from you.

Thanks in advance, 

Laurin Buchanan, CISSP
Information Security 
MSC Industrial Direct
v: 516.812.1358
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