User Acceptance Testing

User Acceptance Testing

Once the application is ready to be released the crucial step is User Acceptance Testing.

In this step a group representing a cross section of end users tests the application.

The user acceptance testing is done using real world scenarios and perceptions relevant to the end users.

What is User Acceptance Testing?

User Acceptance Testing is often the final step before rolling out the application.

Usually the end users who will be using the applications test the application before ‘accepting’ the application.

This type of testing gives the end users the confidence that the application being delivered to them meets their requirements.

This testing also helps nail bugs related to usability of the application.

User Acceptance Testing – Prerequisites:

Before the User Acceptance testing can be done the application is fully developed.

Various levels of testing (Unit, Integration and System) are already completed before User Acceptance Testing is done. As various levels of testing have been completed most of the technical bugs have already been fixed before UAT.

User Acceptance Testing – What to Test?

To ensure an effective User Acceptance Testing Test cases are created.

These Test cases can be created using various use cases identified during the Requirements definition stage. The Test cases ensure proper coverage of all the scenarios during testing.

During this type of testing the specific focus is the exact real world usage of the application. The Testing is done in an environment that simulates the production environment.

The Test cases are written using real world scenarios for the application

User Acceptance Testing – How to Test?

The user acceptance testing is usually a black box type of testing. In other words, the focus is on the functionality and the usability of the application rather than the technical aspects. It is generally assumed that the application would have already undergone Unit, Integration and System Level Testing.

However, it is useful if the User acceptance Testing is carried out in an environment that closely resembles the real world or production environment.

The steps taken for User Acceptance Testing typically involve one or more of the following:

1. User Acceptance Test (UAT) Planning
2. Designing UA Test Cases

3. Selecting a Team that would execute the (UAT) Test Cases
4. Executing Test Cases
5. Documenting the Defects found during UAT
6. Resolving the issues/Bug Fixing
7. Sign Off

User Acceptance Test (UAT) Planning:

As always the Planning Process is the most important of all the steps. This affects the effectiveness of the Testing Process. The Planning process outlines the User Acceptance Testing Strategy. It also describes the key focus areas, entry and exit criteria.

Designing UA Test Cases:

The User Acceptance Test Cases help the Test Execution Team to test the application thoroughly. This also helps ensure that the UA Testing provides sufficient coverage of all the scenarios.

The Use Cases created during the Requirements definition phase may be used as inputs for creating Test Cases. The inputs from Business Analysts and Subject Matter Experts are also used for creating.

Each User Acceptance Test Case describes in a simple language the precise steps to be taken to test something.

The Business Analysts and the Project Team review the User Acceptance Test Cases.

Selecting a Team that would execute the (UAT) Test Cases:

Selecting a Team that would execute the UAT Test Cases is an important step.

The UAT Team is generally a good representation of the real world end users.

The Team thus comprises of the actual end users who will be using the application.

Executing Test Cases:

The Testing Team executes the Test Cases and may additional perform random Tests relevant to them

Documenting the Defects found during UAT:

The Team logs their comments and any defects or issues found during testing.

Resolving the issues/Bug Fixing:

The issues/defects found during Testing are discussed with the Project Team, Subject Matter Experts and Business Analysts. The issues are resolved as per the mutual consensus and to the satisfaction of the end users.

Sign Off:

Upon successful completion of the User Acceptance Testing and resolution of the issues the team generally indicates the acceptance of the application. This step is important in commercial software sales. Once the User “Accept” the Software delivered they indicate that the software meets their requirements.

The users now confident of the software solution delivered and the vendor can be paid for the same.

What are the key deliverables of User Acceptance Testing?

In the Traditional Software Development Lifecycle successful completion of User Acceptance Testing is a significant milestone.

The Key Deliverables typically of User Acceptance Testing Phase are:

1. The Test Plan- This outlines the Testing Strategy

2. The UAT Test cases – The Test cases help the team to effectively test the application

3. The Test Log – This is a log of all the test cases executed and the actual results.

4. User Sign Off – This indicates that the customer finds the product delivered to their satisfaction

Regression Testing...

What is Regression Testing?

If a piece of Software is modified for any reason testing needs to be done to ensure that it works as specified and that it has not negatively impacted any functionality that it offered previously. This is known as Regression Testing.

Regression Testing attempts to verify:

1. That the application works as specified even after the changes/additions/modification were made to it

2. The original functionality continues to work as specified even after changes/additions/modification to the software application

3. The changes/additions/modification to the software application have not introduced any new bugs

When is Regression Testing necessary?

Regression Testing plays an important role in any Scenario where a change has been made to a previously tested software code. Regression Testing is hence an important aspect in various Software Methodologies where software changes enhancements occur frequently.

Any Software Development Project is invariably faced with requests for changing Design, code, features or all of them.

Some Development Methodologies embrace change.

For example ‘Extreme Programming’ Methodology advocates applying small incremental changes to the system based on the end user feedback.

Each change implies more Regression Testing needs to be done to ensure that the System meets the Project Goals.

Why is Regression Testing important?

Any Software change can cause existing functionality to break.

Changes to a Software component could impact dependent Components.

It is commonly observed that a Software fix could cause other bugs.

All this affects the quality and reliability of the system. Hence Regression Testing, since it aims to verify all this, is very important.

Making Regression Testing Cost Effective:

Every time a change occurs one or more of the following scenarios may occur:

- More Functionality may be added to the system

- More complexity may be added to the system

- New bugs may be introduced

- New vulnerabilities may be introduced in the system

- System may tend to become more and more fragile with each change

After the change the new functionality may have to be tested along with all the original functionality.

With each change Regression Testing could become more and more costly.

To make the Regression Testing Cost Effective and yet ensure good coverage one or more of the following techniques may be applied:

- Test Automation: If the Test cases are automated the test cases may be executed using scripts after each change is introduced in the system. The execution of test cases in this way helps eliminate oversight, human errors,. It may also result in faster and cheaper execution of Test cases. However there is cost involved in building the scripts.

- Selective Testing: Some Teams choose execute the test cases selectively. They do not execute all the Test Cases during the Regression Testing. They test only what they decide is relevant. This helps reduce the Testing Time and Effort.

Regression Testing – What to Test?

Since Regression Testing tends to verify the software application after a change has been made everything that may be impacted by the change should be tested during Regression Testing. Generally the following areas are covered during Regression Testing:

- Any functionality that was addressed by the change

- Original Functionality of the system

- Performance of the System after the change was introduced

Regression Testing – How to Test?

Like any other Testing Regression Testing Needs proper planning.

For an Effective Regression Testing to be done the following ingredients are necessary:

- Create a Regression Test Plan: Test Plan identified Focus Areas, Strategy, Test Entry and Exit Criteria. It can also outline Testing Prerequisites, Responsibilities, etc.

- Create Test Cases: Test Cases that cover all the necessary areas are important. They describe what to Test, Steps needed to test, Inputs and Expected Outputs. Test Cases used for Regression Testing should specifically cover the functionality addressed by the change and all components affected by the change. The Regression Test case may also include the testing of the performance of the components and the application after the change(s) were done.

- Defect Tracking: As in all other Testing Levels and Types It is important Defects are tracked systematically, otherwise it undermines the Testing Effort.

Correlation & Regression

Ref: Nayyar Raza Kazmi...

Correlation

1. Shows strength of association between two variables
2. Tells us how much the two variables are associated with each other
3. However, does not assume CAUSATION
4. Simply tells us whether the two variables are positively or negatively correlated

Regression

If there is a strong correlation between two variables, Regression is used to determine Y (dependent variable) from the X's (Independent variables on which Y depends)

Types of regressions: Linear, Multiple...

You use Coefficient of Correlation (r) as to measure the strength of relationships between two variables

r is also called Pearson's Coefficient.

r can range from -1 to +1

Values of -1 or +1 indicate strong correlation (-1 perfect negative relationship (inverse relationship) and +1 perfect positive correlation)

Values close to 0.0 indicate weak correlation