1. The purpose of “Impacted-By” is to help in Risk identification and analysis. We are trying to explicitly identify and Document factors, which we believe influence the results. This will hopefully Result in specific Action or design to keep those Impacts from threatening our planned results.
2. The more general purpose of Impacted-By, and many other Planguage relationship mechanisms, is to build a “web of connections” between specifications (that is, between System components). This web of connections serves many purposes. Risk management was mentioned above. Other uses are configuration management, System familiarization, Quality-Control, estimation, contracting, prioritization, and reviewing.
4. For strong primary intended Impacts, the “Supports” icon can be used, A ->> B. meaning A is primarily the way we intend to achieve the Requirement/value B.
This Concept entered by Kay Dudman