DW Toolkit Chapter 1 Defining Business Requirements

DW Lifecycle Dimensional Modeling Project Planning Business Requirements Definition Physical Design ETL Design & Development Deployment Growth Maintenance BI Application Specification BI Application Development Technical Architecture Design Product Selection & Installation Project Management

Gathering Enterprise-Level Requirements Prepare Conduct Business Interviews Conduct IT Interviews Write up Interview Summaries Identify Business Processes Conduct Prioritization Session Write Requirements Definition Use Data Profiles to Research Data Sources Build Initial Bus Matrix

The interview process The Interview Documentation Themes and processes The bus architecture Conduct Business Interviews Conduct IT Interviews Write up Interview Summaries Identify Business Processes Build Initial Bus Matrix

What do you want to know? What is the problem area? How does the business you approach it? Is the data available? Who will use the results? Who cares?

Subjects Business Executive What are the business issues? What is your vision? Business Manager or Analyst What are your measures of success? What data do you use? What analysis do you typically do? Data Audit Data quality or quantity issues? Potential roadblocks (political or technical)? How is ad hoc analysis conducted?

Results of the interviews Analytic themes and business goals Themes: fundamental questions that the business wants answered Goals: state that the business seeks to Business processes: sources of data to support analytic themes Dimensions: entities or categories that define the themes Business value: how much is solving the problem worth

Interviews Individual or group Roles Lead Interviewer Scribe Pre-interview research Questionnaire Agenda User Preparation Write-up

Interview Roles Lead Interviewer(s): direct the questions and adapt to the conversation Scribe: take notes. interject if the lead interviewer misses something. write up the session Observer (not more than two) observe – not participate

The interview process Introduce everyone: make everyone feel comfortable. Introduce the subject Remember your role Verify communication Define terminology Establish peer basis: know interviewees vocabulary and business understanding

The interview process (cont.) Be flexible be prepared to schedule additional interviews respect your interviewees time and reschedule if needed Avoid burnout don’t schedule too many at once leave time between sessions Manage Expectations

The interview process (cont.) Wrap up the interview Summarize Ask for permission to call back Get documentation Write up the interview soon (2 hours to 2 days)

Tape recorders Cannot really replace people Ask first May make subjects nervous Require listening to the meeting twice

Facilitated sessions Each one takes more time than interviews, but may generate more Requires an experienced facilitator Requires an initial understanding of the user area Participants feed of each others ideas Participants can negotiate disagreements

Caveats The one question to never ask is “What do you want in your computer system?” That is your job, not theirs. You need to be brave enough to ask executives what keeps them up at night? The interview team needs to resist the temptation to focus only on the top 5 reports or top ten questions. Continually manage expectations.

Bus Matrix ProcessDateProductVendorShipperDist Cntr StorePromo Purchase Orders XXXX Dist Cntr Deliveries XXXXX Dist Cntr Inventory XXX Store DeliveriesXXXXX Store InventoryXXX Store SalesXXXX

Bus Matrix The rows of the bus matrix correspond to business processes  data marts Separate rows should be created if: the sources are different, the processes are different, or a row represents more than what can be tackled in a single implementation iteration. Creating the DW bus matrix is a very important up-front deliverable of a DW implementation. The DW bus matrix is a hybrid resource: technical design tool, project management tool, and communication tool.

Requirements Findings Document (Business Case) Establishes the relevance and credibility of the data warehouse project. Ties the business requirements to the realistic availability of data.

Prioritization High Low High Business Value HighLow Feasibility

Initial Project High value Strong sponsorship Low difficulty Moderately visible Single data source