My first Publication Agile-Data-Warehouse-Design-eBook | Page 16

I NTRODUCTION Dimensional modeling, since it was first popularized by Ralph Kimball in the mid- 1990s, has become the accepted (data modeling) technique for designing the high performance data warehouses that underpin the success of today’s business intelli- gence (BI) applications. Yet, with an ever increasing number of BI initiatives stumbling long before they reach the data modeling phase, it has become clear that Data Warehousing/Business Intelligence (DW/BI) needs new techniques that can revolutionize BI requirements analysis in the same way that dimensional modeling has revolutionized BI database design. Dimensional Agile, with its mantra of creating business value through the early and frequent delivery of working software and responding to change, has had just such a revolu- tionary effect on the world of application development. Can it take on the chal- lenges of DW/BI? Agile’s emphasis on collaboration and incremental development coupled with techniques such as Scrum and User Stories, will certainly improve BI application development—once a data warehouse is in place. But to truly have an impact on DW/BI, agile must also address data warehouse design itself. Unfortu- nately, the agile approaches that have emerged, so far, are vague and non- prescriptive in this one key area. For agile BI to be more than a marketing reboot of business-as-usual business intelligence, it must be agile DW/BI and we, DW/BI professionals, must do what every true agilist would recommend: adapt agile to meet our needs while still upholding its values and principlFs (see Appendix A: The Agile Manifesto). At the same time, agilists coming afresh to DW/BI, for their part, must learn our hard-won data lessons. Agile techniques With that aim in mind, this book introduces BEAM ✲ (Business Event Analysis & Modeling): a set of collaborative techniques for modelstorming BI data require- ments and translating them into dimensional models on an agile timescale. We call the BEAM ✲ approach “modelstorming” because it combines data modeling and brainstorming techniques for rapidly creating inclusive, understandable models that fully engage BI stakeholders. This book is about BEAM ✲ modelers achieve this by asking stakeholders to tell data stories, using the 7W dimensional types—who, what, when, where, how many, why, and how—to describe the business events they need to measure. BEAM ✲ models support mod- elstorming by differing radically from conventional entity-relationship (ER) based models. BEAM ✲ uses tabular notation and example data stories to define business events in a format that is instantly recognizable to spreadsheet-literate BI stakeholders, yet easily translated into atomic-detailed star schemas. By doing so, BEAM ✲ bridges the business-IT gap, creates consensus on data definitions and generates a sense of business ownership and pride in the resulting database design. BEAM✲ is used for modeling is responsible for today’s DW/BI successes, yet we still struggle to deliver enough BI can help, but they must address data warehouse design, not just BI application development BEAM✲: an agile approach to dimensional modeling modelstorming BI requirements directly with BI stakeholders XVII