Financial%20Data%20Model%20Overview

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Financial Data Model Overview

• Daniel Grieb
• Lori Silvestri

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Agenda

• Reporting Solution
• Star Schema Primer
• Data Modeling Process
• Finance Data Models
• Design Challenges and Choices
• Implementation
• Conclusion

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Finance Data Modeling Guidelines

• Campus Solution must use CSU Finance Reporting
  Solution as Source
• Replace Existing
• Revenue and Expense (P L)
• Trial Balance Reporting
• Drill from Summary to Transaction
• Need daily refresh of large data sets
• Anticipate analytical reporting

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Levels of Reporting
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• REPORTING SOLUTION

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CSU Reporting Solution

• Attribute Tables
• one set for each Set ID
• XXCMP, XXCSU, XXGAP
• Transaction Tables
• separate tables per Business Unit
• Summary Table
• XXCMP and XXCSU
• Brothwell, Kist, and Yelland, Finance 9.0
  Reporting Solution Training April, 2008

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CSU Reporting Solution - Attributes

• Attribute Tables one set for each Set ID
  (XXCMP, XXCSU, XXGAP)
• Fund CSU_R_FUND_TBL
• Department CSU_R_DEPT_TBL
• Account CSU_R_ACCT_TBL
• Program CSU_R_PRGM_TBL
• Project CSU_R_PROJ_TBL
• Class CSU_R_CLASS_TBL
• Can be joined to transaction and summary tables
• Department table contains flattened version of
  the campus organization department tree
• Brothwell, Kist, and Yelland, Finance 9.0
  Reporting Solution Training April, 2008

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CSU Reporting Solution - Transactions

• Transaction Tables separate tables per Business
  Unit
• Campus Business Unit Transaction Tables
• Actuals CSU_R_ACTDT_CMP
• Budgets CSU_R_BUDDT_CMP
• Encumbrances CSU_R_ENCDT_CMP
• Pre-Encumbrances CSU_R_PREDT_CMP
• CSU Business Unit Transaction Tables
• GAP Business Unit Transaction Tables
• Brothwell, Kist, and Yelland, Finance 9.0
  Reporting Solution Training April, 2008

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CSU Reporting Solution - Summary

• Summary Tables (XXCMP and XXCSU)
• Campus Business Unit Summary Table
• CSU_R_SUMBL_CMP
• CSU Business Unit Summary Table
• CSU_R_SUMBL_CSU
• Brothwell, Kist, and Yelland, Finance 9.0
  Reporting Solution Training April, 2008

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Benefits of the Reporting Solutionto the
Dimensional Data Model

• Validated independently
• Reporting solution was validated between January
  and September 2008
• Finance was heavily invested in, helped design
  and trusted the reporting solution
• Sped up data model validation because we could
  tie to the reporting solution
• Finance validated within days, rather than weeks
• Validated using the dashboards

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Benefits of the Reporting Solutionto the
Dimensional Data Model

• Reporting solution now used in parallel by
  Finance for internal querying and to fill ad hoc
  requests
• Phase one of the data models did not have to
  incorporate all of the reporting solution data
• Helped constrain project scope

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• STAR SCHEMA PRIMER

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What Is a Star Schema

• The star schema is perhaps the simplest data
  warehouse schema. It is called a star schema
  because the diagram of this schema resembles a
  star, with points radiating from a central table.
  The center of the star consists of a large fact
  table and the points of the star are the
  dimension tables.

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Star Schema Database Design
Star Schema - a data model that consists of one
fact table and one or more dimension tables
Dimension Table
Dimension Table
Fact Table
Contains facts and/or measures to be analyzed
(i.e., amount, count, etc.) and foreign keys
(keys to dimension tables)
Dimension Table
Dimension Table
Dimension Table Contains attributes describing
a campus entity (i.e., department, account type,
ledger, etc.)
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Star Schema
WHO?

• Fact tables contain process activity located in
  the center (quantitative data) Some example facts
  are monetary amount, budget amount and statistics
  amount
• Dimensions tell the story and provide the detail
  to the facts. Which departments budget? When
  was the last transaction posted for a given
  account?

THE FACTS
WHERE?
WHAT?
WHEN?
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Star Schema Benefits

• Data model is easy to understand
• Based on business process
• Easy to define hierarchies
• City-State-Country
• Day-Accounting Period-Fiscal Year
• Easy to navigate
• Number of table joins reduced
• Star schema recognized by leading query tools
• Maintainable and Scalable
• Dimension tables shared between data models
• Can add new fact tables which use existing
  dimensions

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Why Star Schema for Cal Poly Finance?

• Dimensions can easily be reused
• across current and future finance models
• Superior query performance for large datasets
• i.e., over 5 million rows
• Usability
• Understandable for users
• Better support unanticipated questions
• Star schemas are extremely compatible with
  business intelligence query tools such as OBIEE.

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• DATA MODELING PROCESS

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Data Modeling Process

• Interactive/ Iterative Process
• Requirements Gathering
• Domain research
• Data profiling
• Modeling tool
• Design sessions with data steward

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Data Modeling Process Requirements Gathering

• Primarily Done by Reporting Solution Development
• Our Requirement Refashion Reporting Solution
  into a Dimensional Model
• Performance
• Accessibility

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Data Modeling Process Research

• Domain research
• Finance
• Cal Poly Financials
• Cal Poly Reports (nVision, Brio)
• Industry Finance Models (Kimball)
• Data profiling
• Querying reporting solution
• Correlating fields/ values
• Matrix of Attributes Across Document Sources

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Data Modeling Process Design

• Modeling tool
• Needed a tool to support efficient design
• Limitations of modeling tools like Visio
• Embarcadero ER Studio
• Design sessions with data steward
• model reviews
• Validated groupings of attributes into dimensions
• New (non-reporting solution) sources
• (i.e., dept, prog and proj trees)
• prototyping dashboards

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• FINANCE DATA MODELS

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Cal Poly Finance Data Models

• 4 data models implemented to date
• 22 Dimensions
• Reused across models
• Chart fields, Business unit, Ledger, etc
• 4 Fact tables
• Actual Transactions
• Budget Transactions
• Encumbrance Transactions
• Actual, Budget and Encumbrance Summary

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Who (Dept ID, Vendor, etc)
Actual Fact
High Level Finance Data Model Diagram
What (Account, Fund, etc)
Budget Fact
When (Acctg. Period, Fiscal Year, etc.)
Encumbrance Fact
Where (Business Unit, etc)
Summary Fact
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Model Overview Actual, Budget and Encumbrance
Summary
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Model Overview Actual Transactions
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Model Overview Budget Transactions
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Model Overview Encumbrance Transactions
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Closer Look at a Dimension

• Department
• FINANCE_DEPARTMENT
• Initial source was CSU Reporting Solution
  Department Attribute table
• PS_CSU_R_DEPT_TBL

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Closer Look at a Dimension

• Source Department table
• contains flattened version of campus
  organization department tree
• Ragged hierarchy
• Added additional source data Cal Poly
  department tree
• Non-ragged hierarchy
• Robust hierarchy for data exploration
• Supports reporting on department reorganization
  or renaming
• Cal Poly users are accustomed to using this tree

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Closer Look at Department Dimension

• Department Budget Specialist and Manager
• Reporting Solution provides a single manager
  field
• Cal Poly Needs Primary and Secondary Budget
  Specialists and Managers
• Available for querying and display in reports
• Used for access control in Finance dashboards -
  filtering / ease of use
• Source Excel Spreadsheet
• Provided by Finance
• Updated weekly
• Plan to create mini-web application to capture
  data in future

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Department Dimension
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• Presentation of Data Models

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Transactional vs. Summary Models

• Dimensions in the summary model are a subset of
  those in the transactional models
• Allows for drill-across from summary to
  transactional models
• Feels like a drill-down

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• Design Challenges and Choices

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Design Challenges

• Challenge
• Reporting solution is denormalized
• PolyData typically sources normalized data
  sources and manages denormalization
• Solution
• Took us a little outside of our comfort zone
• Deconstructed the reporting tables into unique
  combinations of elements

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Design Challenges

• Challenge
• Attributes are overloaded
• For example, a document_id can represent an
  invoice number, a PO number, a journal
  identifier, etc.
• Solution
• Preserved this concept in the dimensional models
  because it is familiar to Finance

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Design Challenges

• Challenge
• Uniqueness not enforced in the reporting solution
• Solution
• Added an instance number for identical
  transactions

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Design Challenges

• Challenge
• Nightly rebuild of the reporting solution
  potentially deletes rows
• Solution
• Effective-dated transactions in the fact

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Design Challenges

• Challenge
• Transactional and summary reporting tables may
  not tie
• journal vs. ledger sources
• summing the detail may give the wrong answer
• Solution
• This is a known issue to which Finance is
  accustomed
• Opportunity for a dashboard integrity report

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Design Challenges - Naming

• Challenge
• Reporting Solution names did not conform with
  PolyData Warehouse standards
• Solution
• Data Warehouse standards
• Field and table names use full English words when
  possible for usability
• Codes precede corresponding description (Code,
  Descr)
• Used reporting solution names with full spelling
  and adding Code and Descr where appropriate.

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Design Choices Slowly Changing Dimensions

• Most dimensional attributes were determined by
  data steward to be slowly changing dimension Type
  1 (SCD1).
• Exception Department Table
• SCD1 attributes such as department description
• SCD2 department tree data
• IF you need to track historical changes to
  dimensions
• You may need to source dimensions from source
  system(s)
• Candidates include chart fields, vendors,
  customers

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Design Choices SCD Example

• Cal Poly needs department tree history
• Department tree data
• Slowly Changing Dimension Type 2 - preserves
  history
• Effective date rows (effective from and to dates)
• Add new row for each change
• All other department attributes
• Slowly Changing Dimension Type 1 overwrites
  history
• Replace old/outdated data with current

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Design Choices New Sources

• In design and prototyping sessions with end
  users, it became apparent that additional source
  data was needed
• New non-reporting solution sources were needed to
  supplement existing source.
• Department tree
• Program tree
• Project tree
• Design change from using only reporting solution
  as source

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• IMPLEMENTATION

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Time and Resources

• Modeling/Domain familiarization
• 2 data modelers
• June through August 2008
• Source-to-Target analysis and documentation
• 2 analysts
• July through September 2008

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Time and Resources

• Coding and system integration
• 4 ETL programmers
• August through October 2008
• Total person-days
• July through October 2008
• Approximately 140 person-days

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Time and Resources

• Caveats
• Established documentation methods and coding
  standards
• Slowly changing logic developed or provided by
  toolset
• 3 transactional models implemented identically

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Nightly Build
Job Minutes (approximate)
Source pull 30
Reporting solution build 70
Data model build 140
End user table refresh 60
TOTAL 300
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Performance TuningNightly Build

• Coordination with Finance on their builds
• Nightly processing
• Reporting solution (in transactional database)
• Approximately one month to level out on timing
• Tuning specific to the finance jobs
• Coordination with other PolyData warehouse jobs

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Performance TuningEnd-User Tables

• Performance was reasonable prior to indexing
• Largely due to the dimensional structure
• Performance screamed after indexing
• Indexes on fields used in selection criteria and
  drillable hierarchies
• Bitmap indexes on foreign keys in facts

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Implementation Interface with Front End
Developers

• joins should be fully documented
• front end developers may need some training in
  interpreting models
• we still have not come up with an ideal method
  for documenting hierarchies
• challenge - knowledge of hierarchies is shared
• data steward
• front end developers
• modelers

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• CONCLUSION

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Future Work

• Labor Cost
• GAAP Reporting
• Management Dashboard/Analytics
• Integration with HR and Student Data

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Questions?

• Daniel Grieb
• Data Warehouse Architect, Analyst/Programmer
• Lori Silvestri
• Data Warehouse Analyst/Programmer

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Contact

• OBIEE Technical Conferencehttp//polydata.calpol
  y.edu/dashboards/obiee_conf/index.html
• Email polydata_at_calpoly.edu