Jackie McDougall - Learning to Love Data - EuroSTAR 2010

Unissons nos Talents

T O G E T H E RT A L E N T E D

1

Jackie McDougall

[email protected]

07894 607776

Learning to L♥ve Data Warehouse Testing

2Learning to Love Data Warehouse Testing

Investigating Data Warehouses

Project Background

Testing Approach

Client plan

IdealMy Initial Thoughts

My View

Lessons Learned

The Way Forward

Agenda



THE TRUTH IS OUT THERE …


What is a data warehouse?

“A warehouse is a subject-orientated, integrated, time-variant and

non-volatile collection of data in support of management’s decision making process” Source: “What is a Data Warehouse?” W.H. Inmon, 1995

“A data warehouse is a copy of transaction data specifically structured for query and analysis”. Source: “The Data Warehouse Toolkit” R. Kimball, 1996

A Data Warehouse is NOT a traditional relational database…

What’s the difference?



UK Public sector client

Government directive to achieve certain

heat targets by next year

Solution was going to be ETL of data

from existing sources to single Data

Warehouse

Third party providing warehouse

solution

Reports to ascertain if/when threshold

levels reached/breached

Project Background


Testing Approach – the Client’s Plan

Ref Data &

Data Load Test

18th Dec – 6th Jan

Dec

2009

January

2010

March

2010

April

2010

February

2010

Warehouse

Implemented

14th – 17th Dec

Pathway

Matching

14th – 20th

Validation Test

7th – 13th

Test Preparation

9th Jan – 27th Feb

Redevelopment

28th Jan – 3rd Feb

Archive DL & Report Testing

3rd Feb – 9th Mar

Real-time DL & Report Testing

17th – 30th Mar

Redevelopment

10th – 16th Mar

User Report Testing

31st Mar – 21st Apr

Key: Dev Team

IT Project Team

Info Dept

Users

Live

26th Apr


Testing Approach – Ideal

ETL Target

(DW)Reports

Source

Data

Staging

Data

•Count records

In source files•Count records in each

part of staging

•Count records

In target (DW)

•Count target

displayed in reports

E T L U

•Check all fields (directly extracted and

derived/calculated)

•Check all fields

displayed in reports

3rd Party Supplier

System Test


Test resources

Test Manager brought in

Engaged with other users

(Data Quality staff, Info

Dept testers, (beta)

testers)

Formal test strategy

What Environment

What Data

Inclusions/Exclusions

Resources

Acceptance Criteria

Stripped back test scripts

Release Process

Defect Management

Risks and Assumptions

Testing Approach – My Initial Thoughts

SIT – ETL Requirements Testing Risk Based Testing Scheduled regression

testing

SIT – reports Exploratory Testing

UAT – ETL Reconciliation Acceptance criteria

UAT - reports early previews


Testing Approach – My View

ETL Target

(DW)Reports

Source

Data

Staging

Data

E T L U

Perfect world testing…

•Sample check key

fields for calculated/

derived data

•Sample check data load

of transaction data and

reference data

•Sample check

data validation/

error process

•Reconciliation

Project Team

Pre-UAT/

Sanity check

•Reports

User Acceptance

Testing

r

TOP 10 COMMON PATHWAYS

(RISK BASED/

SCENARIO APPROACH)


Testing Approach – My View (SIT)


Lessons Learned

Define your quality entry criteria that you expect from your supplier

Insist your development team/supplier provides adequate

design/development documentation

Get the requirements right (or at least fixed!) and test them

Consider data quality and when it gets addressed

Get a test strategy (a real one)

Get the right (skilled) resources on board (early)

Think carefully about the reconciliation exercise

Consider how (the project team) will support the solution going

forward


The Way Forward?

Create a DW testing ‘companion’ – crib sheet for fellow users of things to think about at different stages

System Test/SIT – examine how I can formalise this with colleagues and use techniques like requirements testing, RBT, exploratory testing to help them…

UAT – promote the Top 10 common pathways approach (combination of RBT/scenario testing)

Learn more about DW and BI

Phase 1 Testing? – still ongoing

Independent Review of solution to aid Phase 2 planning

Established test & supporting processes will be maintained

Re-use of test scripts and data possible

Potential for use of test tools in the future


Thank You

Advice for me or questions?

Jackie McDougallSenior Test Consultant

Testing Services Group

Carnbroe House, Finch Way

Strathclyde Business Park

Bellshill, North Lanarkshire

ML4 3PR

Tel : +44(0)1698 574249

Mob:+44(0)7894 607776

Mail : [email protected]

Jackie McDougall - Learning to Love Data - EuroSTAR 2010

Technology

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