In systems thinking terminology, alpha is "an important object of attention" (whose progress should be tracked to track the overall progress of the project or assess the health of the project). Alpha-of and sub-alpha-of are the corresponding types of ontological relationships.
Seven main alphas can be extracted in almost any project (not necessarily software development project, albeit the framework of alphas (OMG Essence) was originally developed by Ivar Jacobson for software projects):
Look for a surprise when making the system schema of the project.
‣ when making the system schema. Prototype to buy information to improve results and save effort down the road, during the implementation of the project.