The Data Flow Diagram gives us information of the flow of data within the application.
•The DFD can be used to analyze the design of the application.
•It is a graphical representation of the structure of the data.
•A developer draws context level DFD first showing interaction between the different components of the application.
•DFD help in developing the software by clarifying the requirements and major functionalities.
•DFDs show the flow of data through a system.
•It is an important modeling tool that allows us to picture a system as a network of functional processes.
Preventative tests are designed early; reactive tests are designed after the software has been produced.
When tester performs testing of application by using random input from the input domain of the system, this is Random Testing.
Random testing involve following procedures:
•Selection of input domain.
•Randomly selecting any input from input domain.
•Using these test input testing of application is performed.
•The results are compared to the system specification. The test is a failure if any input leads to incorrect results, otherwise it is a success.
By analyzing a final product the process of recreating a design is known as reverse engineering. Reverse engineering is the process followed in order to find difficult, unknown, and hidden information about a software system. It is important when software products lack proper documentation, and are highly unstructured, or their structure has degraded through a series of maintenance efforts. Maintenance activities cannot be performed without a complete understanding of the software system.
Bug Leakage: When customer or end user discovered a bug which can be detected by the testing team. Or when a bug is detected which can be detected in pervious build then this is called as Bug Leakage.
Bug release: is when a build is handed to testing team with knowing that defect is present in the release. The priority and severity of bug is low. It is done when customer want the application on the time. Customer can tolerate the bug in the released then the delay in getting the application and the cost involved in removing that bug. These bugs are mentioned in the Release Notes handed to client for the future improvement chances.
The advantages of the waterfall model are:
•Simple to implement and required fewer amounts of resources.
•After every phase output is generate.
•Help in methods of analysis, design, coding, testing and maintenance.
•Preferred in projects where quality is more important than schedule and cost.
•Systematic and sequential model.
•Proper documentation of the project.
User Acceptance Testing (UAT) is performed by the end users on the applications before accepting the application.
Alpha testing: is performed by the IN-House developers. After alpha testing the software is handed for the Beta testing phase, for additional testing in an environment that is similar to the client environment.
Beta testing: is performed by the end user. So that they can make sure that the product is bug free or working as per the requirement. IN-house developers and software QA team perform alpha testing. The public, a few select prospective customers or the general public performs beta testing.
Gamma Testing: Gamma Testing is done when the software is ready for release with specified requirements. This testing is done directly by skipping all the in-house testing activities.
Benchmarking testing is the process of comparing application performance with respect to industry standard which is given by some other organization. Benchmark informs us where our application stands with respect to others. Benchmark compares our application performance with other company’s application’s performance.
A test harness is a collection of software and test data required to test the application by running it in different testing condition like stress, load, data- driven, and monitoring its behavior and outputs. Test Harness contains two main parts:
•Test execution engine
•Test script repository
Automation testing is the use of a tool to control the execution of tests and compare the actual results with the expected results. It also involves the setting up of test pre-conditions.
A software review can be defined as a filter for the software engineering process. The purpose of any review is to discover errors in the analysis, design, and coding, testing and implementation phases of the software development cycle. The other purpose of a review is to see whether procedures are applied uniformly and in a manageable manner. It is used to check the process followed to develop the software is right.
Verification: process of evaluating work-products of a development phase to determine whether they meet the specified requirements for that phase.
Validation: process of evaluating software during or at the end of the development process to determine whether it specified requirements.
Difference between Verification and Validation:
•Verification is Static Testing where as Validations is Dynamic Testing.
•Verification takes place before validation.
•Verification evaluates pl, document, requirements and specification, where as Validation evaluates product.
•Verification inputs are checklist, issues list, walkthroughs and inspection ,where as in Validation testing of actual product.
•Verification output is set of document, pl, specification and requirement documents where as in Validation actual product is output.
Five test cases are required to test:
@Enter the data in all the mandatory fields and submit, should not display error message.
@Enter data in any two mandatory fields and summit, should issue an error message.
@Do not enter in any of the fields should issue an error message.
@If the fields accept only number, enter numbers in the fields and submit, should not issue an error message, try to enter only in two fields should issue an error message, and enter alphabets in two fields and number in other two fields it should issue an error message.
@If the fields do not accept special characters, then enter the characters and submit it.
Exploratory testing: me testing an application without a test plan and test script. In exploring testing test explore the application on the basis on his knowledge. The tester has no knowledge about the application previously. He explores the application like an end user and try to use it. While using the application his main motive is to find the bugs which are in the application.
•The Stub is called from the software component to be tested. It is used in top down approach.
•The driver calls a component to be tested. It is used in bottom up approach.
•Both test stub and test driver are dummy software components.
We need test stub and test driver because of following reason:
•Suppose we want to test the interface between modules A and B and we have developed only module A. So we cannot test module A but if a dummy module is prepare, using that we can test module A.
•Now module B cannot send or receive data from module A directly so, in these cases we have to trfer data from one module to another module by some external features. This external feature used is called Driver.
The purpose of exit criteria is to define when a test level is completed.
Baseline testing is the process of running a set of tests to capture performance information. Baseline testing use the information collected to made the changes in the application to improve performance and capabilities of the application. Baseline compares present performance of application with its own previous performance.
•Branch Coverage is testing performed in order to ensure that every branch of the software is executed atleast. To perform the Branch coverage testing we take the help of the Control Flow Graph.
•Decision coverage testing ensures that every decision taking statement is executed atleast once.
•Both decision and branch coverage testing is done to ensure the tester that no branch and decision taking statement, will not lead to failure of the software.
•To Calculate Branch Coverage:
Branch Coverage = Tested Decision Outcomes / Total Decision Outcomes.
Concurrency Testing is used to know the effects of using the software by different users at the same time. In this type of testing we have multiple users performing the exact same requests at the same time. It helps in identifying and measuring the problems in Response time, levels of locking and deadlocking in the application. For this we use Load runner to create VUGen (Virtual User Generator) is used to add the number of concurrent users and perform operation on the application on the same time.
Cyclomatic complexity is used to measure the complexity of the software using the control flow graph of the software. It is a graphical representation, consisting of following:
NODE: statement of the program is taken as node of the graph.
Edges: the flow of command is denoted by edges. Edges are used to connect two node , this show flow of control from one node to other node in the program.
Using this node and edges we calculate the complexity of the program. This determines the minimum number of inputs you need to test always to execute the program.
Compatibility testing is to evaluate the application compatibility with the computing environment like Operating System, Database, Browser compatibility, backwards compatibility, computing capacity of the Hardware Platform and compatibility of the Peripherals. Example, If Compatibility testing is done on a Game application, before installing a game on a computer, its compatibility is checked with the computer specification that whether it is compatible with the computer having that much of specification or not.
The RAD model Rapid Application development (RAD) is incremental software development process models that focus on the development of the project in very short time. It is enhanced version of Waterfall model. It is proposed when requirements and solutions can be made independently system or software components, which is developed by different teams. After these smaller system components are developed, they are integrated to produce the large software system solution.
Compatibility testing is a type of testing used to find out the compatibility between the application and platform on which application works, web browsers, hardware, operating systems etc. Good software must be compatible with different hardware, web browser and database.
Statement Coverage is a metric used in White Box Testing. Statement coverage is used to ensure that all the statement in the program code is executed at least once. The advantages of Statement Coverage are:
•Verifies that written code is correct.
•Measures the quality of code written.
•Determine the control flow of the program.
•To Calculate Statement Coverage:
•Statement Coverage = Statements Tested / Total No. of Statements.
The advantages of this type of testing include:
•Developer and tester are independent of each other.
•The tester does not need knowledge of any programming languages.
•The test is done from the point-of-view of the user.
•Test cases can be designed when specifications are complete.
•Testing helps to identify issues related to functional specifications.
Mutation testing is a performed to find out the defect in the program. It is performed to find put bugs in specific module or component of the application. Mutation testing is based on two assumptions:
Competent programmer hypothesis: according this hypothesis we suppose that program write the correct code of the program.
Coupling effect: according to this effect collection of different set of test data can also find large and complex bugs.
After finding the bug the first step is bug to be locked in bug report. Then this bug needs to be communicated and assigned to developers that can fix it. After the bug is fixes by the developer, fixes should be re-tested, and determinations made regarding requirements for regression testing to check that fixes didn't create problems elsewhere.
An inspection is more formalized than a walkt hrough. Inspection technique involves 3 to 8 team member consisting of a moderator, reader, and a recorder to take notes. The subject of the inspection is typically a document such as a requirements or a test plan, and the purpose is to find problems and see what is missing, most problems will be found during this preparation. The result of the inspection meeting should be a written report. It is one of the most cost effective methods of ensuring quality.
There are four types of maintenance. They are:
Software Requirements Specification (SRS) is documented form of the requirement of the customer. It consists of all requirement of the customer regarding that software to be developed. The SRS document work as agreement between the company and the customer consisting of all functional and non functional requirements.
Business Requirement Specification (BRS) are the requirements as described by the business people. The business tells “what” they want for the application to do. In simple word BRS contain the functional requirement of the application.
V model: it is enhanced version of waterfall model where each level of the development lifecycle is verified before moving to next level. In this testing starts at the very beginning. By testing we mean verification by me of reviews and inspections, static testing. Each level of the development life - cycle has a corresponding test plan. A test plan is developed to prepare for the testing of the products of that phase. Be developing the test pl, we can also define the expected results for testing of the products for that level as well as defining the entry and exit criteria for each level.
•Retesting is done to verify defect fix previous in now working correctly where as regression is perform to check if the defect fix have not impacted other functionality that was working fine before doing changes in the code.
•Retesting is specific and is performed on the bug which is fixed where as in regression is not be always specific to any defect fix it is performed when any bug is fixed.
•Retesting concern with executing those test cases that are failed earlier where as regression concern with executing test cases that was passed in earlier builds.
•Retesting has higher priority over regression.
Agile Testing me to quickly validation of the client requirements and make the application of good quality user interface. When the build is released to the testing team, testing of the application is started to find the bugs. As a Tester, we need to focus on the customer or end user requirements. We put the efforts to deliver the quality product in spite of short time frame which will further help in reducing the cost of development and test feedbacks will be implemented in the code which will avoid the defects coming from the end user.
In this situation is for the testers to go through the process of reporting of bugs with the focus being on critical bugs. Since this type of problem can severely affect schedules, and indicates deeper problems in the software development process project managers should be notified, and provided with some documentation.
Alpha testing: is performed by the IN-House developers. After alpha testing the software is handed over to software QA team, for additional testing in an environment that is similar to the client environment.
Beta testing: beta testing becomes active. It is performed by end user. So that they can make sure that the product is bug free or working as per the requirement. IN-house developers and software QA team perform alpha testing. The public, a few select prospective customers or the general public performs beta testing.
Monkey testing is a type of Black Box Testing used mostly at the Unit Level. In this tester enter the data in any format and check the software is not crashing. In this testing we use Smart monkey and Dumb monkey.
Smart monkeys are used for load and stress testing, they will help in finding the bugs. They are very expensive to develop. Dumb monkey, are important for basic testing. They help in finding those bugs which are having high severity. Dumb monkey are less expensive as compare to Smart monkeys.
Example: In phone number filed Symbols are entered.
Decision table testing is used for testing systems for which the specification takes the form of rules or cause-effect combinations. In a decision table the inputs are listed in a column, with the outputs in the same column but below the inputs. The remainder of the table explores combinations of inputs to define the outputs produced.
We need Test Strategy for the following reasons:
@To have a signed, sealed, and delivered document, where the document contains details about the testing methodology, test plan, and test cases.
@Test strategy document tells us how the software product will be tested.
@Test strategy document helps to review the test plan with the project team members.
@It describes the roles, responsibilities and the resources required for the test and schedule.
@When we create a test strategy document, we have to put into writing any testing issues requiring resolution.
The test strategy is decided first, before lower level decisions are made on the test plan, test design, and other testing issues.
•The bug is assigned to development project manager who will analyze the bug .He will check whether it is a valid defect. If not valid bug is rejected then status is REJECTED.
•If not, next the defect is checked whether it is in scope. When bug is not part of the current release .Such defects are POSTPONED
•Now, Tester checks whether a similar defect was raised earlier. If yes defect is assigned a status DUPLICATE
•When bug is assigned to developer. During this stage bug is assigned a status IN-PROGRESS
•Once code is fixed. Defect is assigned a status FIXED
•Next the tester will re-test the code. In case the test case passes the defect is CLOSED
•If the test case fails again the bug is RE-OPENED and assigned to the developer. That’s all to Bug Life Cycle.
There are two types of testing:
•Static testing: Static testing is a technique used in the earlier phase of the development life cycle. The code error detection and execution of program is not concern in this type of testing. Also known as non-execution technique. The Verification of the product is performed in this testing technique like Code Reviews, Inspections, Walkthroughs are mostly done in this stage of testing.
•Dynamic testing: Dynamic Testing is concern with the execution of the software. This technique is used to test the dynamic behavior of the code. Most of the bugs are identified using this technique. These are the Validation activities. It uses different methodologies to perform testing like Unit Tests, Integration Tests, System Tests and Acceptance Testing, etc.
Error Guessing is a test case design technique where the tester has to guess what faults might occur and to design the tests to represent them.
Error Seeding is the process of adding known faults intentionally in a program for the reason of monitoring the rate of detection & removal and also to estimate the number of faults remaining in the program.