Impact Analysis

What is this technique about

Impact analysis is used to identify the potential consequences resulting from a change made to a system. According to Arnold and Bohner (authors who first suggested this technique),  there are three main types of impact analysis:

1. 1. Traceability Impact Analysis: captures the links between requirements, specifications, design elements, and tests, analysing their relationships to determine the scope of an initiating change.
   2. Dependency Impact Analysis: to determine the depth of the impact on the system.
   3. Experiential Impact Analysis: using tacit knowledge and previous experience of an organisation to determine the potential consequences of a change in future.

Where does it come from?

Impact analysis, also known as change impact analysis, was first described in 1996 by American software engineers Robert S. Arnold and Shawn A. Bohner in their book called Software Maintenance. In the book, Arnold and Bohner stated that impact analysis is about “identifying the potential consequences of a change or estimating what needs to be modified to accomplish a change.”

For which purposes it is used (why in your engineering teaching)

Impact analysis is a powerful method to create an understanding among the students of the importance of planning and assessing a change before the change is implemented. It promotes strategic thinking, improves collaboration skills and enhances creativity within solutions. Knowledge of this technique can equip the student with long-term skills, which can positively affect the student in any career path they choose.

How to use it

An impact analysis involves 2 steps. First, we have to find out the relationships related to the subject element, and then we review them to uncover any possible consequences and risks associated with the change. The method of conducting impact analysis changes from organisation to organisation, depending upon the department, the type of change or feature and the type of impact being analysed. However, the impact analysis can be conducted in three generic steps:

1. 1. Preparation: Once the team is decided, the impact analysis’s objectives, goals and scope may be clearly defined. The proposed change should be clearly stated without ambiguity.
   2. Collect information: Brainstorm on the high-level areas impacted by the proposed change (e.g. Customer groups, department strategy, business processes etc.). List all the departments that will be affected by the change. Based on the outcome of the brainstorming, create a questionnaire to collect data from the corresponding departments. If the data is accessible through secondary sources (such as a pre-provided dataset, journals etc.), then the primary data collection may be avoided.
   3. Based on the collected data, analyse the impact. This can be done categorically (indicating benefits and drawbacks) or quantitatively where an impact score is given (higher the score, higher the impact, and a positive score indicates benefits and a negative score indicates drawbacks).