Advantages and Disadvantages Of Automation Testing

This article start with brief Introduction to Automated Testing, Different methods in Automated Testing, Benefits of Automated Testing and the guidelines that Automated testers must follow to get the benefits of automation.

Advantages of Automated Testing

"Automated Testing" is automating the manual testing process currently in use. This requires that a formalized "manual testing process", currently exists in the company or organization. 

Automation is the use of strategies, tools and artifacts that augment or reduce the need of manual or human involvement or interaction in unskilled, repetitive or redundant tasks.

Minimally, such a process includes:

·         Detailed test cases, including predictable "expected results", which have been developed from Business Functional Specifications and Design documentation

·         A standalone Test Environment, including a Test Database that is restorable to a known constant, such that the test cases are able to be repeated each time there are modifications made to the application.

The following types of testing can be automated

·         Functional - testing that operations perform as expected.

·         Regression - testing that the behavior of the system has not changed.

·         Exception or Negative - forcing error conditions in the system.

·         Stress - determining the absolute capacities of the application and operational infrastructure.

·         Performance - providing assurance that the performance of the system will be adequate for both batch runs and online transactions in relation to business projections and requirements.

·         Load - determining the points at which the capacity and performance of the system become degraded to the situation that hardware or software upgrades would be required.

Benefits of Automated Testing

Reliable: Tests perform precisely the same operations each time they are run, thereby eliminating human error

Repeatable: You can test how the software reacts under repeated execution of the same operations. 

Programmable: You can program sophisticated tests that bring out hidden information from the application.
Comprehensive: You can build a suite of tests that covers every feature in your application.

Reusable: You can reuse tests on different versions of an application, even if the user interface changes.

Better Quality Software: Because you can run more tests in less time with fewer resources

Fast: Automated Tools run tests significantly faster than human users.

Cost Reduction: As the number of resources for regression test are reduced.

Choosing the right tools for the job and targeting the right areas of the organization to deploy them can only realize these benefits. The right areas where the automation fit must be chosen.

The following areas must be automated first

1. Highly redundant tasks or scenarios
2. Repetitive tasks that are boring or tend to cause human error
3. Well-developed and well-understood use cases or scenarios first
4. Relatively stable areas of the application over volatile ones must be automated.

Automated testers must follow the following guidelines to get the benefits of automation:

• Concise: As simple as possible and no simpler.

 • Self-Checking: Test reports its own results; needs no human interpretation.

 • Repeatable: Test can be run many times in a row without human intervention.

 • Robust: Test produces same result now and forever. Tests are not affected by changes in the external environment.

 • Sufficient: Tests verify all the requirements of the software being tested.

 • Necessary: Everything in each test contributes to the specification of desired behavior.

 • Clear: Every statement is easy to understand.

 • Efficient: Tests run in a reasonable amount of time.

 • Specific: Each test failure points to a specific piece of broken functionality; unit test failures provide "defect triangulation".

 • Independent: Each test can be run by itself or in a suite with an arbitrary set of other tests in any order.

 • Maintainable: Tests should be easy to understand and modify and extend.

 • Traceable: To and from the code it tests and to and from the requirements.

Disadvantages of Automation Testing

Though the automation testing has many advantages, it has its own disadvantages too. Some of the disadvantages are:
 • Proficiency is required to write the automation test scripts.
• Debugging the test script is major issue. If any error is present in the test script, sometimes it may lead to deadly consequences.
• Test maintenance is costly in case of playback methods. Even though a minor change occurs in the GUI, the test script has to be rerecorded or replaced by a new test script.
• Maintenance of test data files is difficult, if the test script tests more screens.   

Some of the above disadvantages often cause damage to the benefit gained from the automated scripts. Though the automation testing has pros and corns, it is adapted widely all over the world.

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Posted in: Advantages and Disadvantages Of Automation Testing

Waterfall Model

Waterfall model is the first process model to be introduced and widely followed in Software Engineering to ensure the success of the project. In this model, the software development is divided into phases. As the name suggests each phase is frozen before starting the next phase.

We have the following phases in Waterfall model.

Requirement Specification: The requirements of the system to be developed are captured in this phase. Requirements are nothing but the functionalities and constraints expected from the system to be developed. Requirements are gathered from the customer by consultation or some documents. Then the organization will analyze the validity and the possibility of the incorporation of the requirements with the system to be developed. Based on the analysis the “Requirement Specification” document will be prepared. The specification document will serve as a baseline to the next phase.

Design: This phase will take the Requirement Specification as input. Before starting the coding, it is very important to understand what we are going to create and what it should look like. The requirement specification will be studied and the system is designed based on the requirement document. Once the system is designed, the hardware will be identified. Once the system design and hardware are identified, we’ll create the complete system architecture. Creating System Architecture will freeze the design phase.

Implementation & Unit Testing: This will take the System Architecture as input which was developed during Design Phase. In this phase the system is divided into chunks/Units and the actual coding is started. The system is developed as small modules called Units, which will be integrated in next phase. Each unit is developed and tested for its functionality. We call this process as Unit Testing. Unit testing is done by the developer who is developing the corresponding Unit.  This phase is over once the individual Units are developed and tested.

Integration & System Testing: This phase will take the Units developed in “Implementation Phase” as input. During this phase each Units will be integrated with the other Units based on the system architecture. Once the Units are integrated we need to test that the functionalities of integrated Units as System. It means that we are checking, how the Units are functioning when integrated. This is called Integration Testing.  Once the integration is completed based on the system architecture we’ll call it as a “System”. Then we’ll start the system testing. During System testing, we’ll make sure that the developed system is meeting the customer requirements. The developed system will be delivered to the customers once the system testing is over.

Operations & Maintenance: This phase of Waterfall Model is virtually never ending process. Because sometimes issues are not captured during testing phase and will be captured when it’s deployed to the customer. So, we need to fix the issues and deploy it to the customer. This phase is called as Maintenance phase.

Advantages: The main advantage of the waterfall model is the departmentalization and managerial control. In this mode each phase is moved in a strict order without any overlapping or iterative steps.

Disadvantage: The main disadvantage of the model is that it doesn’t allow us to revise. Assume that the product is reached the Testing Phase and customer is requesting for a change. So, it’s very difficult to go back and do the change.  Because it’ll have impact on all phases.

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Posted in: Waterfall Model