MANAGEMENT INFORMATION SYSTEMS （MAN2092）教学：Resolving Many to Many2.pdfVIP

Insights Blogs Resolve your Many-to-Manys for Accurate Requirements October 13, 2014 Resolve your Many-to-Manys for Accurate Requirements Written By: BOB LAMBERT Logical data modeling is one of my tools of choice in business analysis and requirements definition. That’s not particularly unusual – the BABOK (Business Analysis Body of Knowledge) recognizes the Entity-Relationship Diagram (ERD) as a business analysis tool, and for many organizations it’s a non-optional part of requirements document templates. In practice, however, data models in requirements packages often include many-to-many relationships. I’ve heard experienced data modelers advocate this practice, and it unfortunately seems consistent with the “just enough, just in time” approach associated with agile culture. In my experience unresolved M:M relationships indicateequally unresolved business questions. The result: schedule delays and budget overruns as missed requirements are built open in browser PRO version Are you a developer? Try out the HTML to PDF API back in to the design, or the familiar “that’s not what we wanted” reaction during User Acceptance Testing (UAT). What’s a Many-to-many Relationship? An ERD depicts entities, objects, events of interest, and the relationships among them. Relationships between entities are said to have “cardinality”, meaning how many instances of each entity* participate in the relationship. In the case of employees and dependents, one employee may have many dependents (spouse and children, typically), so there is a one-to- many relationship between the entities Employee and Dependent. On the other hand, the relationship between Employee and P