Formal software testing methods

These tests are usually written by the developers of the module and in a test-driven-development methodology such as Agile, Scrum or XP they are actually written before the module is created as part of the specification.

Each module function is tested by a specific unit test fixture written in the same programming language as the module. SpiraTest includes support for the management and execution of automated unit tests.

This testing is usually done with a combination of automated functional tests and manual testing depending on how easy it is to create automated tests for specific integrated components. SpiraTest includes support for storing, managing and coordinating integration tests across various modules and components.

In addition, specifically for E2E and scenario tests, you can assign different test cases in a single test scenario to different testers so that they can work together on an integrated test. With its library of plugins and extensions for different automated functional testing tools including our Rapise automation platform, SpiraTest is the perfect solution for managing your integration testing.

The system testing part of a testing methodology involves testing the entire system for errors and bugs. This test is carried out by interfacing the hardware and software components of the entire system that have been previously unit tested and integration tested , and then testing it as a whole. This testing is listed under the black-box testing method, where the software is checked for u ser-expected working conditions as well as potential exception and edge conditions.

SpiraTest includes support for storing, managing and coordinating system tests across all the modules and components that make up a system. SpiraTest support data-driven testing where test cases are defined with input parameters and different combinations of test data can be passed to the manual and automated tests. This ensures that both expected and exception cases can be tested using the same test frameworks.

This is an activity that is vitally important, since in many cases until you have completed UAT, the customer or organization will not accept the software and sign off on it. Therefore, having a smooth and successful UAT is very important. The key aspect of UAT is that the testers will be end users, who may have significant functional expertise and knowledge, but may be used to how previous systems or processes work, rather than the new system being tested.

It is important to have a tool for them to use that makes the testing process as easy as possible. For example, making it easy to follow the script, ideally interact with the system under test in the same window, and record results, screenshots without unnecessary complexity. In most testing methodologies , functional testing involves t esting the application against the business requirements. Functional testing is done using the functional specifications provided by the client or by using the design specifications like use cases provided by the design team.

Some examples of non-functional testing are described below:. There are several different types of performance testing in most testing methodologies , for example: performance testing is measuring how a system behaves under an increasing load both numbers of users and data volumes , load testing is verifying that the system can operate at the required response times when subjected to its expected load, and stress testing is finding the failure point s in the system when the tested load exceeds that which it can support.

SpiraTest includes support for storing, managing and coordinating your performance, load and stress testing activities. With its library of plugins and extensions for different automated performance testing tools including LoadRunner, JMeter and NeoLoad , SpiraTest is the perfect solution for managing your performance testing.

Previously, security was something that was tested after-the-fact. With the rise in cyber-crime and the awareness of the risks associated with software vulnerabilities, application security is now something that needs to be designed and developed at the same time as the desired business functionality. Security testing tests the software for confidentiality, integrity, authentication, availability, and non-repudiation.

Individual tests are conducted to prevent any unauthorized access to the software code. The usability testing part of a testing methodology looks at the end-user usability aspect of the software. The ease with which a user can access the product forms the main testing point. Usability testing looks at five aspects of testing, - learnability, efficiency, satisfaction, memorability, and errors. The compatibility part of a testing methodology tests that the product or application is compatible with all the specified operating systems, hardware platforms, web browsers, mobile devices, and other designed third-party programs e.

When you can perform compatibility testing using automated tests, one feature that you should really consider having, is a way to do data-driven testing:. This lets you create sets of different test configurations that need to be tested, which are automatically generated by a system e. Agile projects have to test their systems in the same was as traditional waterfall projects, in terms of what kinds of test have to be accounted for.

However, the activities will occur in smaller bursts as part of the iterations or sprints. In addition, the people doing the work may be testing specialists e. In addition, because agile projects deal with a might greater degree of uncertainty and change, you may not have a fully working system, written test cases apart from high level acceptance tests , or even fully formed requirements user stories tend to be quite high level. So there are some techniques that can help. The tester is required to make decisions about what to test next and where to spend a specified amount of time.

Exploratory testing is most useful when there are unclear requirements e. Proving validation is a core process for evaluating models using automatic theorem proofs. This is based on a set of mathematical formulas to be proven called proof obligations Formal Verification.

Standard development techniques revolve around the following phases:. Some may argue that all these steps usually take place, but they must, to some extent for at least usable software with longer perspectives for exploitation. Some of the earlier steps — particularly design stages — may bring a sense of uncertainty in terms of unforeseen problems later in the process.

The reasons could be:. These are just some avoidable factors in the completion of complex projects. Safety-critical systems, in particular, have a significant need for earlier fault detection. It is crucial to validate software faultlessness where agile incremental analysis and development bring about quality assurance concerns.

Thus, that is where the implementation of such techniques finds its highest demand. There are notable differences between standard and formal software development methods. Formal methods are somewhat supporting tools. Here, the reliability of mathematics improves software production quality at any stage. They are not necessarily there to implement data processing.

Choice of programming language is irrelevant. B is an example of formal method techniques that covers the whole development life-cycle. It divides software onto separated components that further represent as Abstract Machines. These are further subject to stepwise refinement and proof obligation evaluation.

Testing is an important part of guaranteeing any system's fitness, but it is finite. Testing cannot demonstrate that a system operates properly; it can only demonstrate that the system works for the tested cases. Because testing cannot demonstrate that the system should work outside the tested cases, formal proof is necessary. Formally proving computer systems is not a new idea. Knuth and Dijkstra have written extensively on the topic, although their methods of proof are based on the traditional mathematical methods.

In pure sciences, proofs are verified through extensive peer review before publication. Such techniques are time-intensive and less than perfect; it isn't unusual for a published proof to contain a flaw. Given the cost and time requirements of systems engineering, traditional proving techniques are not really applicable. Because of the costs of hand verification, most formal methods use automated theorem proving systems to verify their designs.

Automated theorem provers are best described as mathematical CAD tools: they can prove simple propositions and automatically and provide assistance for verifying more complex theorems. Formal methods offer additional benefits outside of provability, and these benefits do deserve some mention. However, most of these benefits are available from other systems, and usually without the steep learning curve that formal methods require.

The discipline involved in formal specification has proved useful even on already existing systems. Engineers using the PVS system, for example, reported identifying several microcode errors in one of their microprocessor designs. An excellent example comes from SML. Handling side effects and other aberrancies are a requirement for any system involving input, network operations or other systems which require interrupts, meaning that SML's model is, to some extent, broken.

The lightweight approach to formal design recognizes that formal methods are not a panacea: there are areas where formal methods are useful, and areas where a formal specification will accomplish nothing. In a lightweight design, formal methods are used in specific locations, and different formal methods may be used in different subsystems, ideally playing to the strengths of each method [Easterbrook 98].

In such a system, Petri Nets might be used to describe the communications protocol, and a LARCH system might be used to model the data storage. For other parts of the system, formal specifications might be avoided entirely: for example, the user interface may be refined using a rapid prototyping system and client interviews.

The lightweight approach is a traditional engineering compromise, and there is a tradeoff.