Driving Implementation Through a Methodology

Chapter 4

“Big Bang” Approach

Analyze enterpriserequirements

Build enterprisedata warehouse

Report in subsets orstore in data marts

“Big Bang” Approach:Advantages and Disadvantages Advantages: - The only real advantage is where the warehouse is being built as part of another major project or program such as reengineering and they are dependent on each other - Having a “big picture” of the data warehouse before starting the data warehousing project Disadvantages: - Involves a high risk, takes a longer time - Runs the risk of needing to change requirements

Incremental Approach to Warehouse Development

Multiple iterationsShorter implementationsValidation of each phase

Strategy

Definition

AnalysisDesign

Build

ProductionStrategy

Definition

AnalysisDesign

Build

Production

Strategy

Definition

AnalysisDesign

Build

Production

Benefits of an Incremental ApproachDelivers a strategic data warehouse solution

through incremental development effortsProvides extensible, scalable architectureSupports the information needs of the enterprise

organizationQuickly provides business benefits and ensures a

much earlier return of investmentAllows a data warehouse to be built based on a

subject or application area at a timeAllows the construction of integrated data mart

environment

Top-Down Approach

SalesSales

MarketingMarketing

Legacy data

Operational data

External data source

Datawarehouse

Datamarts

Users

Top-Down Approach:Advantages and Disadvantages

Advantages: - Provides a relatively quick implementation and payback - Offers significantly lower risk - Emphasizes high-level business needs - Achieves synergy among subject areas Disadvantages: - Requires an increase in up-front costs - Difficult to define the boundaries - May not be suitable unless the client needs cross-functional reporting

Bottom-Up Approach

SalesSales

MarketingMarketing

Legacy data

Operational data

External data source

Datawarehouse

Datamarts

Bottom-Up Approach:Advantages and Disadvantages Advantages: - Appealing to IT - Easier to get buy-in from IT Disadvantages: - Requires source systems to encapsulate the current business processes - Design may be out-of-date before delivery - Requires reengineering for each increment - Solutions may be rejected by the next line of business to be involved

- Overall benefit to the business may be minimized

Oracle Method

Consists of: - Online guidelines and manuals - Workplan templates - Deliverable templatesCreated by experienced and field-

based practitioner for estimated, managing, developing, and delivering business solutions.

Oracle Data Warehouse Method

Guides through development: - Business functions - Processes - TasksModeled on the Custom

Development Method

Method Materials

Workplan templates*Deliverable

templates*Online handbooksEstimating software

Software Tools Handbooks

Method handbookProcess and task

reference*Deliverable

reference*

Oracle Data Warehouse Method

Focuses on scopingManages riskRelies on user involvement throughoutDelivers an extensible, scalable solutionUses a variety of technologies Identifies tasks with clear objectives and

deliverablesEmploys common techniques, skills, and

dependenciesAssigns tasks to processes and processes to phases

Benefits

Experience and best practices

Flexibility

Risk avoidanceProductivity

Consistency

DWM Fundamental ElementsApproachesPhasesProcessesTasks and deliverablesRoles

Phase 1 Phase 2 Phase 3

Process 1

Process 2

Phase 1 Task1Phase 1 Task2Phase 1 Task3

Phase 2 Task1Phase 2 Task2Phase 2 Task3

Phase 3 Task1Phase 3 Task2Phase 3 Task3

Approaches

Increment IProof of Concept

Warehouse Businessinfrastructure application

implementation implementation

Increment IIThrough N Through N

Increment II

Data mart

Data mart

Data mart

Warehouse

Packageddata mart

Incremental Approach

Warehouse StrategyPhase

Scoping Services

Technical ArchitectureServices

Increment 1 Increment AProof of Concept

Increment 2

Increment 3

Increment n

Increment B

Increment C

Increment z

WarehouseInfrastructure

Services

WarehouseBusiness Solution

Services

RequirementsCapture

BusinessStrategy

ITStrategy

Incremental Development Focus on business functionality Deliver business benefit Suited to warehouse evolution Once an increment is complete the

selection and scope of the next increment is defined Each increment

follows the same phase sequence

Strategy

PGMPJMProject

andProgram

Management

Definition

ETAEnterpriseTechnical

Architecture

Analysis

Design

Build

Transition to Prod.

Discovery

IncrementalDevelopment

The Strategy Phase

Strategy

Analysis

Design

Build

Transition

Discovery

DefinitionBusiness requirements

Data acquisition

Architecture

Data quality

Administration

Strategy

The Strategy Phase

Strategy

Analysis

Design

Build

Transition

Discovery

DefinitionMetadata

Data access

Documentation

Testing

Training

Strategy

The Definition Phase

Strategy

Analysis

Design

Build

Transition

Discovery

DefinitionBusiness requirements

Data acquisition

Architecture

Data quality

Definition

The Definition Phase

Strategy

Analysis

Design

Build

Transition

Discovery

DefinitionAdministration

Metadata management

Data access

Documentation

Training

Definition

The Analysis Phase

Strategy

Analysis

Design

Build

Transition

Discovery

DefinitionBusiness requirements

Data acquisition

Architecture

Data quality

Administration

Analysis

The Analysis Phase

Strategy

Analysis

Design

Build

Transition

Discovery

DefinitionMetadata

Data access

Documentation

Testing

Training

Analysis

The Design Phase

Strategy

Analysis

Design

Build

Transition

Discovery

Definition Data acquisition

Metadata management

Architecture

Data quality

Administration

Design

The Design Phase

Strategy

Analysis

Design

Build

Transition

Discovery

Definition Data access

Database design & build

Documentation

Testing

Training

Design

Transition

The Build Phase

Strategy

Analysis

Design

Build

Transition

Discovery

Definition Data acquisition

Metadata management

Architecture

Data quality

Administration

Build

The Build Phase

Strategy

Analysis

Design

Build

Transition

Discovery

Definition Data access

Database design & build

Documentation

Testing

Training

Build

Transition

Transition to Production Phase

Strategy

Analysis

Design

Build

Transition

Discovery

Definition Data acquisition

Post-implementation support

Testing

Training

Transition

Transition to production

Discovery Phase

Strategy

Analysis

Design

Build

Transition

Discovery

Definition

Post-implementationsupport

Discovery

Processes

Cohesive set of tasks that meet objectives

Common skill setProject deliverables Most overlap and interrelate; others

are strict predecessors

Processes

Business Requirements DefinitionData Acquisition

ArchitectureData Quality

Warehouse AdministrationMetadata Management

Data AccessDatabase Design and Build

DocumentationTesting

TrainingTransition

Post-Implementation Support

Business Requirements Definition

Defines requirementsClarifies scopeEstablishes implementation road mapProvides initial focus on enterprise

implementationIdentifies information needsModels the requirements

Data Acquisition

Identify, extract, transform, and transport source data

Consider internal and external dataMove data between sources and targetPerform gap analysis between source data and

target database objectsDefine first-time load and refresh strategyDefine tool requirementsBuild, test, and execute data acquisition

modules

ArchitectureSpecify technical foundationCreate warehouse architectural design Integrate products of architecture components for

scalability and flexibilityDetermine database environment--distributed or

centralizedDefine development, testing, training, and

production environmentsConfigure the platformPerform database sizingConsider disk striping

Data QualityEnsure data consistency, reliability, accuracyDevelop a strategy for: - Cleansing - Integrity functions - Quality management procedures Identify business rules for: - Cleansing - Error handling - Audit and controlDefine data quality tool requirementsBuild, test, and execute data quality modules

Warehouse Administration

Specify maintenance strategy for: - Configuration management - Warehouse management - Data governingDefine warehouse management workflow and

tool requirementsBuild, test, and execute modulesProve data access management and monitoringAutomate warehouse management tasks

Metadata Management

Define metadata strategyDefine metadata typesSpecify requirements for the metadata

repository, integration, and accessEstablish technical and business views

of metadataDevelop modules for capturing,

bridging, and accessing metadata

Data Access

Identify, select, and design user access toolsDefine user profilesDetermine requirements for interface style,

queries, reports, and the end user layerEvaluate, acquire, and install access objects - Queries and reports - Catalogs - Hierarchies and dimensions

Database Design and BuildSupport data requirementsProvide efficient accessCreate and validate logical and physical modelsCreate relational and multidimensional database

objectsEvaluate partitioning, segmentation, and

placement Identifying indexes and keysGenerate DDLBuild and implement database objects

Documentation

Produce textual deliverables:GlossaryUser and technical documentationOnline helpMetadata reference guideWarehouse management referenceNew features guide

Testing

Develop a test strategy Create test plans, scripts, and scenarios Test all components:

- Data acquisition - Data Access - Ad hoc access - Regression - Volume - Backup - Recovery Support acceptance testing

TrainingDefine requirements: - Technical - End user - BusinessIdentify staff to be trainedEstablish time framesDesign and develop materialsFocus on tool training and use of the

warehouse

Transition

Define tasks for transitioning to the production warehouse

Migrate modules and proceduresDevelop the installation planPrepare the maintenance

environmentPrepare the production environment

Post-Implementation Support

Evaluate and review warehouse useMonitor warehouse useRefresh the warehouseMonitor and respond to problemsConduct performance testing and tuningTransfer responsibilityEvaluate and review the implemented

solution

Tasks and DeliverablesOutlined in Work Breakdown StructureOrganized by process and phase

Task ID Task Name

A Strategy A. RD.EXEC Business Requirements Definition A.RD.001 Obtain Existing Reference Material A.RD.002 Obtain Reference Data Models A.RD.003 Define Strategic Goals, Vision of the Enterprise A.RD.004 Establish Business initiatives A.RD.005 Define Objectives and Purpose of Enterprise Data Warehouse A.RD.015 Collect Enterprise Business Information Requirements

Roles

The project team: roles and responsibilities

Common roles Analyst, database administrator,

programmer, testerWarehouse specific roles DW architect, metadata architect, data

quality administrator, DW administrator

Warehouse Technology Initiative

Customer driven - Warehouse products only - Quality, not quantity - High-value partnershipsRequires - Oracle certified solution partner level - Product certification - Reference

WTI Partners by Categories

Design and administrationSourceManageAccessData content provider

Summary

This lesson discussed the following topics:Explaining the different approaches to

warehouse development and the benefits of an incremental approach

Identifying the purpose of the Oracle MethodDiscussing the purpose and fundamental

elements of Data Warehouse MethodDiscussing the objectives of the Oracle

Warehouse Technology Initiative