Software Testing interview questions Explain the PDCA cycle.
PDCA cycle stands for Plan Do Check Act; commonly used for quality control.
Plan: Identify aim and procedure necessary to deliver the output.
Do: Implement the plan.
Check: Confirm if the result is as per plan.
Action: Take appropriate action to deceiver expected outcome. Which may also involve repeat the cycle. What are white-box, black-box and gray-box testing?
White Box testing: white box testing involves thorough testing of the application. It requires knowledge of code and the test cases chosen verifies if the system is implemented as expected. It typically includes checking with the data flow, exceptions, and errors, how they are handled, comparing if the code produces the expected results.
E.g. In electrical appliances the internal circuit testing.
Black Box testing: Black box testing is done at an outer level of the system. Test cases merely check if the output is correct for the given input. User is not expected to the internal flow or design of the system.
Gray Box testing: Grey box testing is a combination of both black box and white box testing. This is because it involves access to the system; however, at an outer level. A little knowledge of the system is expected in Gray box testing. Explain the difference between Latent and Masked Defect.
Latent defects are defects which remain in the system, however, identified later. They remain in the system for a long time. The defect is likely to be present in various versions of the software and may be detected after the release.
E.g. February has 28 days. The system could have not considered the leap year which results in a latent defect
Masked defect hides other defects in the system. E.g. there is a link to add employee in the system. On clicking this link you can also add a task for the employee. Let’s assume, both the functionalities have bugs. However, the first bug (Add an employee) goes unnoticed. Because of this the bug in the add task is masked. What is Big-bang waterfall model?
The waterfall model is also known as the Big-bang model because all modules using waterfall module follows the cycle independently and then put together. Big Bang model follows a sequence to develop a software application. It slowly moves to the next phase starting from requirement analysis followed by design, implementation, testing and finally integration and maintenance. What is configuration Management?
Configuration management aims to establish consistency in an enterprise. This is attained by continuously updating processes of the organization, maintaining versioning and handling the entire organization network, hardware and software components efficiently.
In software, Software Configuration management deals with controlling and tracking changes made to the software. This is necessary to allow easy accommodation of changes at any time. What is Boundary value Analysis?
Test cases written for boundary value analysis are to detect errors or bugs which are likely to arise while testing for ranges of values at boundaries. This is to ensure that the application gives the desired output when tested for boundary values.
E.g. a text box can accept values from minimum 6 characters to 50 characters. Boundary value testing will test for 5 characters, 6 characters, 50 characters and 51 characters. What is Equivalence Partitioning?
Equivalence partitioning is a technique used in software testing which aims to reduce the number of test cases and choose the right test cases. This is achieved by identifying the “classes” or “groups” of inputs in such a way that each input value under this class will give the same result.
E.g. a software application designed for an airline has special offer functionality. The offer is that first two member of every city booking the ticket for a particular route gets a discount. Here, the group of inputs can be “All cities in India”.
Explain Random testing.
Random testing as the name suggests has no particular approach to test. It is an ad hoc way of testing. The tester randomly picks modules to test by inputting random values.
E.g. an output is produced by a particular combination of inputs. Hence, different and random inputs are used. What is Monkey testing?
Monkey testing is a type of random testing with no specific test case written. It has no fixed perspective for testing. E.g. input random and garbage values in an input box. Explain Software Process.
A software process or software development process is a method or structure expected to be followed for the development of software. There are several tasks and activities that take place in this process. Different processes like waterfall and iterative exists. In these processes; tasks like analysis, coding, testing and maintenance play an important role. What is Maturity level?
Maturity level of a process defines the nature and maturity present in the organization. These levels help to understand and set a benchmark for the organization.
Five levels that are identified are:
Level 1: Adhoc or initial
Level 2: Repeatable
Level 3: Defined
Level 5: Optimized
What is process area in CMMI?
Process areas in Capabilty Maturity model describe the features of a products development. These process areas help to identify the level of maturity an organization has attained. These mainly include:
Project planning and monitoring
Process and Product quality assurance
Configuration management Explain about tailoring.
Tailoring a software process means amending it to meet the needs of the project. It involves altering the processes in different environments, it’s an ongoing process. Factors like customer and end user relation ship, goals of business must be kept in mind while tailoring. Degree to which tailoring is required must be identified. What are staged and continuous models in CMMI?
Staged models in CMMI, focus on process improvement using stages or maturity levels. In staged representation each process area has one specific goal. Achieving a goal would mean improvement in control and planning of the tasks associated with the process. Staged representation has 5 maturity levels.
Continuous model in CMMI follow a recommended order for approaching process improvement within each specified process area. It allows the user to select the order of improvement that best meets the organization’s business objectives. Continuous representation has 6 capability levels. Explain capability levels in continuous representation.
There are 6 capability levels for Continuous representation:
Level 0: Not performed
Level 1: Performed
Level 2: Managed
Level 3: Defined
Level 4: Quantitatively managed
Level 5: Optimizing
Each level has process areas. Each process area has specific goals to achieve. These processes are continuously improved to achieve the goals in a recommended order. What is SCAMPI process?
Standard CMMI Appraisal Method for Process Improvement provides a benchmark relative to Maturity Models. It describes requirements, activities and processes associated with each process area. The SCAMPI appraisals identify the flaws of current processes. It gives an idea of area of improvement and determines capability and maturity levels.