Partnering with the business

Transcription

1 Dimensional Modeling while Partnering with the Business Community Laura L. Reeves February, 2012 Agenda Current data warehousing climate Partnering with the business Focus on the data The Business Dimensional Model (BDM) Putting it all together Slide 2 1

2 Critical Challenges How can you deliver more. with fewer resources? How can you increase the value of what you deliver? What does the changing technology landscape mean to you? Slide 3 Reflection How would your business users grade you? Slide 4 2

3 Common DW Climate DW may fall short of business expectations Too hard to use It takes too long to get new reports or add more data Disconnect between IT and the Business Business Perspective IT does not deliver what we need Build solutions ourselves IT Perspective Business can t tell us what they really want Build it for them and expect them to use it Slide 5 Time to Set A New Direction 3

4 Getting the Right Tools Slide 7 What does not change? People Data Slide 8 4

5 Partner with the Business Slide 9 Strengthen Your IT Team Invest now in your staff Practice critical skills Listening Writing Communication Collaboration Some people will thrive, but not everyone wants to or has aptitude to transition to this new world. Slide 10 5

6 Cultivate Problem Solvers Provide exposure to new ideas and approaches If the only tool you have ever used is a hammer, then everything begins to look like a nail. Encourage curiosity Reward creativity Continue to invest in learning new technologies Slide 11 Invest in Your IT-Business Partnership Make conscious choices to build partnership Start by changing your behavior IT needs to take time to learn about the business Speak in business terms Keep technology out of the discussion Business needs to actively participate Learn basics of DW/BI Solicit ideas/suggestions from each other Slide 12 6

7 Understand True Business Requirements Gather broad business requirements Understand business goals, plans and challenges How is success measured? What information is needed to help make decisions? Actively collaborate Detailed specifications will be needed later to flesh out specific report design, dashboards, ETL business rules Slide 13 Business Requirements Drive Decisions to jointly scope projects that deliver business value and are achievable Business should drive purpose and direction IT evaluates feasibility and effort Work together to determine how to deliver value today and into the future Set priorities Determine return on investment Ensure everyone understands why you are doing this work Slide 14 7

8 Focus On The Data Slide 15 Delivering Data to the Business Must be easy to understand Good query performance required Dimensional models specifically target these goals Delivered through a variety of technologies Relational database Star or snowflake schemas Multi-dimensional database Cube Other proprietary databases Columnar DW appliance Slide 16 8

9 The Modeling Technique The Business Dimensional Model TM Reflect data model visually and in business terms Ensures support for various types of reporting and analysis Independent of technology Ideal training tool for use later Manageable approach to complex environments Year Quarter Month DAY Slide 17 Basics of Dimensions Dimensions are major business categories or groupings to describe business data Dimensions contain: Descriptive elements Reference data Attributes, hierarchies, drill paths Dimensions are used for: Selection criteria Report labels Pick list via interface Slide 18 9

10 Date Dimension Example Fiscal Year Multiple Hierarchies Calendar Year Fiscal Quarter Calendar Quarter Attributes Fiscal Month Calendar Month Future Attribute Fiscal Week Week Holiday Grain for this Dimension Day Day of Week Slide 19 Complete Dimension Documentation ATTRIBUTE NAME BRIEF DESCRIPTION SAMPLE VALUES Day Calendar day information was reported on. 6/31/2003, 9/1/2003 Holiday Fiscal Week Fiscal Month Fiscal Quarter This is a future attribute to indicate that this date is considered a U.S. business day off. The week of the fiscal year that the date rolls up to and is used for reporting purposes. The month of the fiscal year that this date rolls up to and is used for reporting purposes. The quarter of the fiscal year that this date rolls up to and is used for reporting purposes. Memorial Day, President s Day FY 2003 Week 16 FY , FY FY 2003-Q1, FY 2003-Q2 Fiscal Year The year that this date rolls up to based upon the company s fiscal calendar. FY 2003 Calendar Month The calendar month used for reporting purposes. March 2003, October 2003 Calendar Quarter The calendar quarter used for reporting purposes. CY 2003-Q1, CY 2003-Q2 Calendar Year The calendar year used for reporting purposes. CY 2003 Week The calendar week ending Saturday and is used for reporting purposes. Week Ending 11/21/1998 Day of Week Attribute to indicate the calendar day of week. Wednesday, Saturday Slide 20 10

11 Basics of Facts Facts are the basic business events that are measured and monitored Facts are typically: Amounts and Counts Defined by more than one dimension Numeric (frequently, but not always) Facts are used as: Body of reports Part of calculations Slide 21 Sales Fact Group Example Dimension Name Grain for the Fact Group for this Dimension Product Item Sales Outlet Store Facts: Dollars Units Price Cost Name of Fact Group Promo Promo Date Day Slide 22 11

12 Complete Fact Group Documentation FACT NAME Dollars Units Price Cost FACT DEFINITION The dollar amount for the Units Sold. The number of consumer units sold. The actual price charged for this sale. The standard price factor for this item sold at this store. AGGREGATION RULE Sum Sum Average Average Slide 23 Dimensional Model - The Star Schema Product Dimension PRODUCT KEY Product Descr Size Flavor Package Promotion Dim. PROMO KEY Promo Descr Deal Discount Media Fact Table PRODUCT KEY STORE KEY PROMO KEY DATE KEY Dollars Units Price Cost Outlet Dimension STORE KEY Store Name District Region Zone Date Dimension DATE KEY Day Weekday Holiday Fiscal Period Slide 24 12

13 A BDM Case Study Slide 25 BDM Example: Period Dimension Fiscal Year Calendar Year Fiscal Quarter Calendar Quarter Fiscal Month Calendar Month Fiscal Week Week Holiday Day Day of Week Slide 26 13

14 BDM Example: Call Center Dimension Division Region Open Date Call Center State Time Zone Call Center Call Center City Slide 27 BDM Example: Employee Dimension Manager Supervisor Date of Birth Educ. Level Employee Hire Date Slide 28 14

15 BDM Example: Client Dimension Corporate Parent Account Executive Client Client City Client State Program Type Program Slide 29 BDM Example: Call Status Dimension Disposition Group Disposition Type Disposition Assigned By Call Disposition Slide 30 15

16 BDM Example: Activities Dimension Task Category Task Group Billable Flag Task Slide 31 BDM Example: Calls Fact Group Call Status Call Disposition Period Day Client Program Facts: # of Calls Call Minutes Calls Activities Dimension does not apply and is not shown Employee Employee Call Center Call Center Copyright 2012 StarSoft Solutions Inc. Slide 32 16

17 Hours Worked Fact Group Call Status Dimension does not apply and is not shown Period Day Facts: Regular Hours Overtime Hours Client Program Activities Task Hours Worked Employee Employee Call Center Call Center Copyright 2012 StarSoft Solutions Inc. Slide 33 Using the Model What are the total number of hours worked to date for people who were hired this year? What are the total number of hours worked by fiscal year and call center region? What are the total calling minutes by call disposition grouped by category? What are the average number of calls for client Our Biggest Customer by fiscal week? Slide 34 17

18 Integration: Conformed Dimensions Call Status Call Disposition Calls Client Program Hours Worked Call Center Call Center Activities Task Slide 35 Translating the BDM Slide 36 18

19 Implementation of BDM Exploit the DB and BI tools Technical design driven by tools BI Tool is the user s only perspective of the DW Database technology helps determine data structure design Every tool has its own unique requirements, recommendations and/or preferences Slide 37 BDM Example: Calling Facts Star Schema Period Table PERIOD KEY Day Day of Week Holidays Fiscal Week Fiscal Month Fiscal Quarter Fiscal Year Calendar Month Calendar Quarter Calendar Year Employee Table EMPLOYEE KEY Employee Name Call Center Fact Table PERIOD KEY PROGRAM KEY CALL DISP. KEY EMPLOYEE KEY CALL CENTER KEY # of Calls Call Minutes Call Center Table CALL CENTER KEY Call Center Name Call Center City Client Table PROGRAM KEY Program Descr Program Type Client Client City Client State Account Executive Corporate Parent Call Status Table CALL DISP. KEY Disposition Descr Disposition Type Disposition Group Hire Date Call Center State Date Of Birth Time Zone Educ. Level Open Date Supervisor Region Manager Division Slide 38 19

20 BDM Example: Hours Worked Star Schema Period Table Client Table PERIOD KEY PROGRAM KEY Day Program Descr Day of Week Program Type Holidays Client Fiscal Week Fiscal Month Fiscal Quarter Fiscal Year Calendar Month Calendar Quarter Calendar Year Hours Worked Fact Table PERIOD KEY PROGRAM KEY TASK KEY EMPLOYEE KEY CALL CENTER KEY Regular Hours Call Center Table Client City Client State Account Executive Corporate Parent Activities Table TASK KEY Task Descr Employee Table Overtime Hours CALL CENTER KEY Billable Flag EMPLOYEE KEY Call Center Name Task Group Employee Name Call Center City Task Category Hire Date Call Center State Date Of Birth Time Zone Educ. Level Open Date Supervisor Region Manager Division Slide 39 Too Many or Too Few Dimensions? Practical Guidelines for a single fact table Minimum 3 4 dimensions Split dimensions that are too broad Consider enterprise view, would that split dimensions apart? Are there more dimensions that could be included for user benefit, but not change the number of rows in the fact table? Maximum 20 Dimensions Are these dimensions really separate? Walk through logical drill paths Slide 40 20

21 Characteristics of Today s Dimensional Models Comprehensive and enterprise perspective drives expanded scope for models Models often have 25+ fact tables dimensions Keep in mind that not all fact tables use all of the dimensions In general each fact group has 5-15 dimensions Slide 41 Developing and Expanding Dimensional Models Design broadly Multiple l user groups for same data Next potential data sources Enterprise viewpoint Plan for conformed dimensions Implement in several increments Don t tackle too much at one time Break into phases Each should deliver business value Review and update the model each time Slide 42 21

22 More BDM Notation BDM Advanced Notation Groups of Future Attributes Unclear groups of attributes Business has not defined these yet To come from a new operational system not designed yet Indicates where these pieces are likely to fit into the model in the future Slide 44 22

23 BDM Advanced Notation Derived Attributes Derived Attributes When there is not a business element with an identifier at this level Used to tie together several hierarchies Perhaps for junk dimensions Slide 45 BDM Advanced Notation Triggers for Type 2 SCD Used to identify those attributes that MUST result in the creation of a new version for that row in the dimension Helps us determine which attributes can be type 1 and which trigger type 2 Slide 46 23

24 BDM Notation Summary Dimension Grain Attribute Derived Attribute Fact Group Future Attribute Slowly Changing Attr Anchor Attribute Collection of Attributes to be Defined in the Future 1- M Relationship M-M Relationship Slide 47 Putting It All Together Slide 48 24

25 Keys to Success Dimensional modeling provides the basic foundation for end user access and analysis Focus on the business requirements and the business user s perspective Designs should reflect clear business dimensions and facts Resulting table structures will likely be influenced by technology Slide 49 Recommended Reading Includes details about Business Dimensional Modeling Slide 50 25

26 Recommended Reading The Data Warehouse Lifecycle Toolkit Ralph Kimball Margy Ross Warren Thornthwaite Joy Mundy Bob Becker John Wiley and Sons, Inc. Second Edition The Data Warehouse Toolkit Ralph Kimball and Margy Ross John Wiley and Sons, Inc. Second Edition The Microsoft Data Warehouse Toolkit Joy Mundy and Warren Thornthwaite John Wiley and Sons, Inc. The Data Warehouse ETL Toolkit Ralph Kimball and Joe Caserta John Wiley and Sons, Inc. Star Schema: The Complete Reference Chris Adamson McGraw Hill Slide East Ogden Ave. Suite Naperville, IL Phone: FAX: Data Warehouse & Business Intelligence Services 26