Tuesday, 19 March 2013

9 Reasons why TDM is critical to a project's success

In my previous posts, I explained about the building blocks of the concepts of Test Data Management (TDM) namely Data Subset, Data Masking, Data Archive, Test Data Refresh, Gold Copy.  Alternatively you might also want to read all articles from the table of contents.  In this post, I will try to explain why TDM is critical to a project's success.

  • Your test data determines the quality of testing
    • No matter how good your testing processes are, if the test data used is not right or of adequate quality, then the entire product's quality will be affected.
  • Your test data should be highly secure
    • It is absolutely mandatory that your test data doesn't contain data from production without being masked.  If the data is not secure enough, then there is every chance that a data breach might happen, which can cause the organization dearly.
  • Test data needs to be as close to real time as possible
    • Not only that test data needs to be of quality, it should be as close to real time data / production data as possible.  Why? Simple reason is we do not want to build a system/application/product for 6 months and fail in the production just because there was not adequate real time data to test.

Wednesday, 13 March 2013

Test Data Life Cycle

In the previous posts, I explained about the various concepts surrounding Test data creation and maintenance, namely Data Subset, Data Masking, Test Data Ageing, Test Data Refresh, Data Archive and Gold Copy.  In this post, I will focus on the life cycle of Test Data.

So what is meant by a life cycle.  Life Cycle is the various stages that a product/service/artifact goes through before attaining its end of life.  So a Test Data Cycle explains the various stages through which the test data goes through in order to reach its end of life or alternatively start a recurring life cycle.

So similar to a test life cycle or a software development life cycle, Test Data goes through the following phases.  They are

Requirement Gathering & Analysis

This is pretty straightforward.  In this phase, the test data requirements pertaining to the test requirements are gathered.  They are categorized into various heads

  • Pain Areas
  • Data Sources
  • Data Security/Masking
  • Data Volume requirements
  • Data Archival requirements
  • Test Data Refresh considerations
  • Gold Copy considerations

This phase is typically carried out in the form of a TDM assessment or Test Data Assessment.  Since that topic requires separate attention, I will dedicate a blog post to it.

Planning & Design

Saturday, 9 March 2013

Gold Copy in Test Data Management (TDM)

In the previous posts, we discussed about Data Subset, Data Masking, Test Data Ageing, Data Archive in TDM and Test Data Refresh.  In this post, we will try to focus on what is Gold Copy in TDM.

So what is meant by Gold Copy?

This is the baseline version of the data that can be used for future releases.  For example,  if you are trying to load your test database from the production database for the first time.  In this case, you can save the copy as a baseline from which future test data refreshes can be made.  The following picture depicts this concept of Gold Copy

Gold Copy - Basics


Thursday, 7 March 2013

Data Archive in Test Data Management (TDM)

In the previous posts, I explained about Data Subset, Data Masking, Test Data Ageing and Test Data Refresh.  In this post, we will focus on the topic of Data Archival and how important it is to the process of Test Data Management.

What does Data Archival typically mean?
  • Size Management
    • You would want to provide an efficient mechanism for the database size management.  Over time a database size grows and you need to actively manage it.
  • Archival of older data
    • Older data can be archived to some low disk space occupying area and can be later retrieved whenever needed

Types or Archive Mechanisms:

Monday, 4 March 2013

What is Test Data Ageing in TDM?

In our previous posts I explained about Data Subset and Data Masking in TDM.  In this post we will focus on Test Data Ageing.

This is useful for Time based testing.  Let's assume you create a customer and it requires 48 hours for activation of that particular customer.  What if you have to test the scenario that will occur after 48 hours? Will you wait till 48 hours for that scenario to happen for your testing? The answer is No.  Then how will you handle this scenario?

There are basically 2 approaches by which we can do this

  • Tamper the system dates
    • Although it is possible in some cases to tamper the system dates and continue with the testing, this method will fail if the date is generated by a database server or an application server instead  of the client.
  • Tamper the dates in the backend
    • This should be most viable and practical solution for such scenario.  In this approach, we modify the date at the backend so that it reflects the new date.  But care should be taken to ensure that data integrity doesn't get lost or the data semantics doesn't get lost.
This method of modifying the date according to the scenario needs is known as Test Data Ageing.  Depending on the scenario that needs to be tested, we can either Back date or Front date the given date.


Saturday, 2 March 2013

Test Data Refresh in TDM

In my previous posts, I explained about Data Subset and Data Masking.  In this post we will focus on the topic of Test Data Refresh.

So what is Test Data Refresh?  It is the process of loading / refreshing the Test Database with the latest data from the Production database or any other data source.

What are the Challenges in Test Data Refresh
  • Diverse data targets
    • Much like the Production data sources, Test data targets can also be across databases and different file systems.  The data needs to be in sync across these targets
  • Test DB can already contain data
    • If it is an existing system, already the Test Database will contain older data.  Steps should be taken to carefully overwrite the data without losing the data integrity.
  • Test DB downtime
    • During the time of test data refresh, it might be necessary to bring down the test environment in order to accommodate the refresh.

Types of Refresh

Wednesday, 27 February 2013

Commonly Used Data Masking Techniques - TDM

In my previous posts I discussed about Data Subset and Data Masking.  In this post, I will discuss the data Masking techniques that are widely used.  This is by no means exhaustive but will provide a general idea of the techniques that are available.

  • Random Substitution
    • In this technique, the value to be masked is replaced or substituted with a random value.  Depending on the nature of the random value, they can be further categorized into
      • Random Numbers
      • Random Dates
      • Random Seed Values For ex.
        • Names
        • Addresses
        • SSN Numbers
        • Credit Card Numbers
        • Telephone numbers
        • And a lot more
      • Random Alphanumerics