Difference between Static and Dynamic Testing

Testing is the most important stage in the Software Development Lifecycle (SDLC). It helps to deliver high-quality products to the end-user and also provides an opportunity for the developer to improve the product. Testing is of many types and is chosen based on the product that is being developed. Static Testing and Dynamic Testing are the two testing techniques that will be discussed in this article.

Static Testing

Static Testing also known as Verification testing or Non-execution testing is a type of Software Testing method that is performed to check the defects in software without actually executing the code of the software application.

1. Static testing is performed in the early stage of development to avoid errors as it is easier to find sources of failures and it can be fixed easily.
2. Static testing is performed in the white box testing phase of the software development where the programmer checks every line of the code before handing it over to the Test Engineer.
3. The errors that can’t not be found using Dynamic Testing, can be easily found by Static Testing.
4. It involves assessing the program code and documentation.
5. It involves manual and automatic assessment of the software documents.

Documents that are assessed in Static Testing are:

1. Test Cases
2. Test Scripts.
3. Requirement Specification.
4. Test Plans.
5. Design Document.
6. Source Code.

Static Testing Techniques

Below are some of the static testing techniques:

1. Informal Reviews: In informal review, all the documents are presented to every team member, they just review the document and give informal comments on the documents. No specific process is followed in this technique to find the errors in the document. It leads to detecting defects in the early stages.
2. Walkthroughs: Skilled people or the author of the product explains the product to the team and the scribe makes note of the review of comments.
3. Technical Reviews: Technical specifications of the software product are reviewed by the team of your peers to check whether the specifications are correct for the project. They try to find discrepancies in the specifications and standards. Technical specifications documents like Test Plan, Test Strategy, and requirements specification documents are considered in technical reviews.
4. Code Reviews: Code reviews also known as Static code reviews are a systematic review of the source code of the project without executing the code. It checks the syntax of the code, coding standards, code optimization, etc.
5. Inspection: Inspection is a formal review process that follows a strict procedure to find defects. Reviewers have a checklist to review the work products. They record the defects and inform the participants to rectify the errors.

Benefits of Static Testing

Below are some of the benefits of static testing:

1. Early detection of defects: Static testing helps in the early detection of defects by reviewing the documents and artifacts before execution, issues can be detected and resolved at an early stage, thus saving time and effort later in the development process.
2. Cost-effective: Static testing is more cost-effective than dynamic testing techniques. Defects found during static testing are much cheaper to find and fix for the organization than in dynamic testing. It reduces the development, testing, and overall organization cost.
3. Easy to find defects: Static testing easily finds defects that dynamic testing does not detect easily.
4. Increase development productivity: Static testing increases development productivity due to quality and understandable documentation, and improved design.
5. Identifies coding errors: Static testing helps to identify coding errors and syntax issues resulting in cleaner and more maintainable code.

Limitations of Static Testing

Below are some of the limitations of static testing:

1. Detect some issues: Static testing may not uncover all issues that could arise during runtime. Some defects may appear only during dynamic testing when the software runs.
2. Depends on the reviewer’s skills: The effectiveness of static testing depends on the reviewer’s skills, experience, and knowledge.
3. Time-consuming: Static testing can be time-consuming when working on large and complex projects.

Dynamic Testing

Dynamic Testing is a type of Software Testing that is performed to analyze the dynamic behavior of the code. It includes the testing of the software for the input values and output values that are analyzed.

1. The purpose of dynamic testing is to confirm that the software product works in conformance with the business requirements.
2. It involves executing the software and validating the output with the expected outcome.
3. It can be with black box testing or white box testing.
4. It is slightly complex as it requires the tester to have a deep knowledge of the system.
5. It provides more realistic results than static testing.

Dynamic Testing Techniques

Dynamic testing is broadly classified into two types:

1. White box Testing: White box testing also known as clear box testing looks at the internal workings of the code. The developers will perform the white box testing where they will test every line of the program’s code. In this type of testing the test cases are derived from the source code and the inputs and outputs are known in advance.
2. Black box Testing: Black box testing looks only at the functionality of the Application Under Test (AUT). In this testing, the testers are unaware of the system’s underlying code. They check whether the system is generating the expected output according to the requirements. The Black box testing is further classified as, Functional Testing and Non-functional Testing.

Benefits of Dynamic Testing

Below are some of the benefits of dynamic testing:

1. Reveals runtime errors: Dynamic testing helps to reveal runtime errors, performance bottlenecks, memory leaks, and other issues that become visible only during the execution.
2. Verifies integration of modules: Dynamic testing helps to verify the integration of modules, databases, and APIs, ensuring that the system is working seamlessly.
3. Accurate reliability assessment: Dynamic testing helps to provide accurate quality and reliability assessment of the software thus verifying that the software meets the specified requirements and functions as intended. This helps to make sure that the software functions correctly in different usage scenarios.

Limitations of Dynamic Testing

Below are some of the limitations of dynamic testing:

1. Time-consuming: Dynamic testing can be time-consuming in the case of complex systems and large test suites.
2. Requires effort: It requires significant effort in complex systems to debug and pinpoint the exact cause.
3. Challenging: In case of testing exceptional or rare conditions it can be challenging to conduct.
4. May not cover all scenarios: Dynamic testing may not cover all possible scenarios due to a large number of potential inputs and execution paths.

Static Testing vs Dynamic Testing

Below are the differences between static testing and dynamic testing:

Parameters	Static Testing	Dynamic Testing
Definition	Static testing is performed to check the defects in the software without actually executing the code.	Dynamic testing is performed to analyze the dynamic behavior of the code.
Objective	The objective is to prevent defects.	The objective is to find and fix defects.
Stage of execution	It is performed at the early stage of software development.	It is performed at the later stage of the software development.
Code Execution	In static testing, the whole code is not executed.	In dynamic testing, the whole code is executed.
Before/ After Code Deployment	Static testing is performed before code deployment.	Dynamic testing is performed after code deployment.
Cost	Static testing is less costly.	Dynamic testing is highly costly.
Documents Required	Static Testing involves a checklist for the testing process.	Dynamic Testing involves test cases for the testing process.
Time Required	It generally takes a shorter time.	It usually takes a longer time as it involves running several test cases.
Bugs	It can discover a variety of bugs.	It exposes the bugs that are explorable through execution hence discovering only a limited type of bugs.
Statement Coverage	Static testing may complete 100% statement coverage incomparably in less time.	Dynamic testing only achieves less than 50% coverage.
Techniques	It includes Informal reviews, walkthroughs, technical reviews, code reviews, and inspections.	It involves functional and non-functional testing.
Example	It is a verification process.	It is a validation process.