ISTQB Certification and Software Testing Principles

Fundamentals of Software Testing

• Software execution is crucial in modern life, and its failure can be devastating.
• Service companies test to avoid failures, bad publicity, and potential lawsuits.
• Software defects can cause various problems, from financial loss and inconvenience to physical harm or fatalities.
• In 2010, millions of Germans couldn't use their credit cards due to a software glitch.
• In 2009, an Airbus A380 had to return to New York due to an autopilot software failure.
• Testing identifies possible failures, helps avoid potential issues, and reduce publicity.
• A missing set of safety code reviews, bad methods and lack of awareness regarding system reliability contributed to massive radiation overdoses of the Thera-25.
• Unit conversion errors in NASA's Mars Climate Orbiter mission led to its loss.
• Three software-related incidents in the space industry each cost hundreds of millions of dollars.
• Software failures result in massive financial losses as a consequence.
• Effective and efficient testing processes are necessary throughout the software product development lifecycle.

Causes, Errors, Defects and Failures

• Human actions, like misinterpreting specifications or making mistakes, are the initial causes, also known as the root cause, of defects.
• Software malfunctions occur when electrical components overheat due to dust exposure.
• Electrical interferences may result from using too many different electronic cables.
• Software malfunctions when electronics components experience a sudden change in heat.
• Solar storms can cause malfunctions when electrical components experience increased solar radiation from unshielded data cables.
• External magnets may disrupt electricity passing through cables.
• Technical terms related to software behavior, such as bug, fault and mistake, are commonly used.
• It is critical for individuals to learn about the discrepancies that result from the definitions that derive the quality that software needs.
• Error is a human action that leads to a defect.
• Defect is the result, present in the test object, of a human action (error).
• Failure is the result of a process executing a defect.
• Implementing training activities, and stricter processes, reduces the number of human errors and defects in software.
• Training activities identify failures by exposing abnormal behavior
• Testers can help designers identify and remove defects with accuracy and efficiency.
• Software defects can be from code errors, and requirements errors, all submitted for analysis and reports.
• Requirements in specifications (user stories) must be specific and easy to comprehend.
• Software is now more complex requiring a new set of safety code for electricity.
• Since defects are more harmful we rely more on their function.

Role of tests in software development, maintenance and operations

• Testing must always be in the software lifecycle, design, maintenance and operation, regardless of how the process goes.
• Rigorous software and system testing reduces the number of defects injected in the process.
• Testing also lowers the probability of failures, to improve high quality software.
• Tests create a more manageable set of data that promotes better management of software quality and project impact..
• Identical tests are not appropriate across contexts, all planning, test processes and techniques need to be adapted to the specific need of each individual project.

Tests and quality

• Tests, quality assurance, and quality control are distinct.
• Quality control and continuous improvement are essential to increase efficacy, efficiency and ensure their efficacy and effectively improves organization.
• Verification that the software is good, through testing detects defects, failures, and data showing risk of release to market and where deliverables can be used.
• Following Agile Manifesto recommendations can better highlight defects, risks and pragmatic evaluation in the testing process.
• There are always betterments found in test approaches and they should be selected based on the specific purpose.

Terminology

• Text starting with FL-xxx indicates learning objectives for certified testers present in the ISTQB foundation level syllabus.
• Chapter titles come from titles of the ISTQB foundation-level syllabus, version 2011.
• Section heads follow the form (FLx.y), corresponding to the chapter and section head of the ISTQB foundation level syllabus.
• A glossary summarizes aspects and terms for certification exams.
• Verification: confirmation, through the provision of objective evidence, that specified requirements have been fulfilled.
• A response to the question: "have we produced what is specified?".
• Validation: confirmation, through the provision of objective evidence, that the requirements for a specific intended use or application have been fulfilled.
• A response to the question: "have we built the correct product?".
• To produce the most accurate results, always conduct verification and validation with testers.

What is testing?

• Testing is a set of activities to pinpoint failures in a software/system to evaluate its degree of quality.
• Testing should obtain user satisfaction, and all tasks should have clear goals.
• A user that finds failures does not make them a tester, a hacker that uses these test cases is still not a tester.

Origin of defects

• Defects are made when the code is written by those that are writing it.
• Different defects and failures have root causes.
• The impact can be summarized as: “error defect/fault failure”.

Common goals of testing

• All testing should not be something to do if there is time between the two design activities, but it should have test objectives.
• Testing goals change, and it is a standard to have test techniques to enable data for delivery to users, taking into account risks, cost reduction, and time to get to the market.
• Defect/failure detection enhances the quality of products delivered to customers/users.
• The decision to be made will be based on risks and the efficiency of the organization, of how the organization processes these defects.

Examples of objectives in testing

• Test objectives depend on the phases of the life cycle of the software.
• The phases are not the same for initial design, maintenance, and during the final software phase.
• Testing focuses on what is necessary to deliver a high quality software.
• Testing during the customer acceptance phase must be with customer satisfaction.
• During all evolutive/corrective maintenance, testing aims to ensure correctness and no side effects occur. Testing will focus on ensuring requirement (SLA) levels are reached.
• If tests are to be replaced it will take a soft snapshot for any present and guarantee good data, all for a new smooth performance.

Test and debugging

• Testing Identifies what characteristics need according to defined procedures.
• When testing is done, and it is determined that all characteristics are not present, then it can be called a 'failure'. To remove all failures the defects should be fixed
• Debugging consists of developers fixing software defects, it is not a task involved in the testing process.

Paradoxes and Main Principles

Testing identifies the presence of defects

• Testing can identify defects but cannot prove the absence of them.
• Testing reduces the risk of residual defects but cannot guarantee their complete absence.

Exhaustive testing is impossible

• Testing everything, including all inputs, actions and configurations, is practically impossible.
• Testing everything with economic feasibility makes design and test executions possible.

Early testing

• Test early in the development cycle to mitigate costs and detect defects early.
• Finding and fixing a defect in the design phase may cost “1”; in the coding phase, “10”; during testing “100”. If it is done before production, it could be up to “1000”.

Defect clustering

• Defects often concentrate in certain areas like complex code sections or components designed by the same person.
• It's efficient to look for other defects in the same block.

Pesticide paradox

• Repetitive tests lose efficiency in identifying new defects.
• Efficacy reduces when its re-executed, but is needed to ensure regression tests are maintained when software is corrected.
• Changing tests regularly, using different techniques, varying test data and execution orders can counter this principle.

Testing is context dependent

• Testing depends on the context, with safety-critical systems tested more intensely than e-commerce websites.
• Adapt tests to your specific environment.

Absence-of-errors fallacy

• Finding defects is not the ultimate goal. Software applications which are defect-free may not suit users for the public if not to their standards.

Test Activities, Testware and Test Roles

• Testing extends beyond software execution, encompassing planning, goal definition, and control.
• The test process must be bespoke.
• Test activities have to be done as an integral part of the planning procedure.

Planning

• Organizing/planning is essential before activity execution.
• Test planning consists of defining goals, identifying constraints, and outlining activities.
• Test planning involves organizing tasks and coordinating with stakeholders.
• The extent of test plan detail depends on the software's nature.

Planning work products

• Common work products post-test planning include test plans and task risk/dependency assessments.

Monitoring and control

• Test monitoring tracks ongoing and future test activities.
• Test control manages deviations by proposing corrective actions.

Monitoring and control work products

• Work products include a summary of the test progress reports.
• Other work products include defection statistics, and risk as well as dependency for relation to the plans.

Test analysis and design

• In the analysis phase, global test objectives are used to create test conditions.
• High-level test objectives are used to create test designs and test procedures.
• Activities include the analysis of the test basis and high-test conditions.

Analysis of the test basis

• Analysis of the test basis involves looking at test objectives.
• A test basis that undergoes changes will be called a “Frozen test basis”.
• Analysis of the test basis enables test and risk identification.
• Integrity level is important for the software and stakeholders.
• Integrity levels depend on the IEEE 829-2008 standards.
• Analysis to the test can help to determine where to test, and allow to quickly change.

Test design

• Goals are implemented throughout design and can be used for test execution.
• Designs are applicable to test conditions and then to test cases.
• Test designs help to apply techniques under any testing conditions.

Test Implementation

• Implementation of test cases help anticipate test execution to show any lower level test conditions.
• Test implementation tasks include organizing test cases, design test environment, maintain traceability etc,.

Test implementation work products

• Common outputs are test procedures, test execution schedules and coverage via traceability.

Test execution

• Test execution identifies variance between expected as well as actual results.
• This includes tracking the information for the test activity to ensure that each test runs and measures the results with the proper status.

Test execution work products

• Work can be achieved by a pass/fail rate, defect reports, and test objects.

Reporting

• Reporting must interest a large number of stakeholders when the project closes.
• Proper plans allow enable people to solve queries when appropriate from the information.
• Reporting is based on test activity.

Test reporting work products

• Products during execution include coverage statistics, and defect reports.
• In addition to product defects, there will also be refinements documented.

Work completion activities

• Following test phases, or reaching the market, activities must to be closed.
• All components must have been delivered
• Defect reports must be fully recorded so stakeholders can follow them up appropriately.
• A good software will have all documentation complete.

Test completion work products

• Work products include, less learned reports and final tests.

The value of Traceability

• Traceability is an integral part of testing and enables in a quality test process.

Impact of context on the test process

• Project factors influence the ability to integrate in development of what is being tested.

Roles in Testing

• The ISTQB defines only two major roles in test:
• Tester: technical aspects with skill to implement cases.
• Test manager: Monitors the coordination, progress, and reporting of test activities among stakeholders.
• Other test jobs can be handled via Agile or by test managers outside the team.

Essential Skills and "Good Practices" in Testing

Generic Skills

• Domain knowledge, technical knowledge, and testing knowledge

Specific Skills

• Deliver bad news or "unwelcome news’ with professionalism to get the project on track.

Whole Team Approach

• Promotes collective knowledge for task completion.
• Acknowledges the value of independent testers.
• In an ideal V-model everyone is responsible for quality, but that is not the case until you begin to system test with system integration.

Levels of Independence

• Testers and developers have individual ways of thinking.
• A developer can become a tester.
• Those doing the designing/coding are the same people doing evaluation.

Adapt to Objectives

• Testers focus on the correct operation of the software, not on finding potential defects.
• Defects are important, but what is more important is that those defects are accurately communicated.
• Providing accurate data.

Question: Destructive or Constructive?

• If development is the only way that testing produces errors, testers will be shown in a better light.

People Skills

• Communication and transmission of data ensures accurate production of the code for safety and software risks.

Change of Perspective

• High output must result from the tester's side to ensure accurate code.

Testers and Code of Ethics

• Ethics are becoming more increasingly important for today's software.

Public

• Testers must act based on laws.

Client and Employer

• Testers should remain professional in the event of any changes made to the clients and employers.

Product

• Certified software testers will ensure the deliverables they provide (on the products and systems they test) to meet the highest standards.

Judgement

• Always maintain integrity in their professional judgement.

Management

• Managers should be able to promote management within testing.

Profession

• Testers ensure high rates for ethics and best behavior.

Colleagues

• Always stay fair with peers.

Self

• Continuously learn in order to increase value as a Tester.

Testing Throughout the Software Life Cycle

Testing through the software development life cycle

• Testing can be applied to almost all development models, but they will be implemented in some form or fashion.
• Any design activity can introduce failures.
• All code should have tasks assigned for identifying and removing failures.
• Sdlcs can have the same test design methods.
• Sequential models are executed in sequence, one after the other, to see what milestones are reached.
• All the development models can be grouped as sequential, iterative or combined.

Sequential models

• Sequential methods help build planning, foundations, and different layers.
• Sequential steps require an order to fit and ensure requirements.
• The waterfall model is a basic sequenced task before the next one.
• Design tests and then after the testing, this can be applied in the project.
• In waterfall models, after a mistake the mistake should not be corrected due to defective initial coding.

The V-model

• Proposed in 1979 and matches each design activity to the test activity of the same level.
• The time between tests and development is a time period in which the model is designed and tested.

W- and VVV-models

• The W-model adds a parallel V models with testing activities and the testing activities of the left hand. The right hand focuses on how to change the test execution of tests and the testing procedures.
• The VVV model is V models where each model is different from the last one. Visualizations are used on the enhancements and corrections, but the Vs are not limited in number.

Iterative models

• With the use of more iterative models with stakeholder input, less stringent specifications can reduce test goals.

Spiral Model

• This model focuses on more detailed analysis for large government systems to measure the costs and analyze possible constraints.

Incremental model

• Incremental development is the planning of subassemblies that all have code/functions that help improve tests.

RAD

• Is an organized model to assemble various modules into a prototype, so clients can give feedback.
• All requirements must be available from the start.
• RAD depends heavily on component architecture.

Agile models

• Cross functional teams
• Rapid iterations for more feedback
• This approach is seen in programming and extreme scrum.

EVO

• A derivation to simplify the tasks split up.

Scrum

• Runs on smaller sprints to provide better quality.

Key elements of all Agile projects:

• Frequent delivery of system level increments
• Helpful data from stake holders.

Test-Driven Development

• Test Before Development. Design code with a mindset to solve the issues in the source code.
• Some Key Points:
• Frequent interaction between Testers, Developers, & Customers.
• Simplest Solutions.

DevOps Approach

• Combine design with ability to deliver to clients.

Selecting A Development Model

• Software is dependent on its ability to perform and be test ready.
• Proper and effective test data is necessary to achieve better results in Testing.
• Proper adaptation of to codes, practices, tooling.

Positioning Tests

• Important to understand as many test levels as possible.
• Focus effort on early points, the best test level.

Test levels and test types

• A number of design activities need to be chosen for types, for example, test environments to identify and solve specific cases

Component tests

• Test Object - Program modules
• Objective - Find the failures in program What we test for:
• Detailed Specifications
• Check Algorithms
• Execute if Available

Integration tests

• Components - Infrastructure, database systems and file systems. How would we test this process?
• See failure in interphases, between components
• Record codes and what exactly will be used
• At least all components must be tested well

System Tests

• Test how the code interacts with other machines as well as general function

Acceptance tests

• Test if software is usable with general audience.
• Make sure all professional standards are up to standard.

Types of Tests

Two Major Distinctions to consider, and how to determine whether you need them or not

• Functional vs Non-Functional
• Functional: code functions as it must
• Non-Functional: focuses on the performance of the product.
• Test early during development.

Tests based on the structure or architecture

• White Box testing to locate errors in segments of code.

Formal Reviews

Informal Reviews

• Run tests with a clear idea how something will perform to verify whether we must continue test.

People

• Tests need developers to get tests.

Other points to think about

• Early testing improves costs
• Isolate all tests for more accurate analysis.

Risk Management

• There is no risk that there is no reward.
• Risk must exist to be worthwhile.

Phases

• Risk Analysis
• Is the process to examine identified risks at each level
• It is easier to avoid certain points to ensure the most appropriate outcomes, while there is more work.

Reviewing Process

• Must know how they are defined.

Test data definition

• The search for test data, in particular, what to test Test for - Functional / Nonfunctional

Configuration management

• Manage different components in a test
• Help to solve issues in the environment.

Change management

• Always test new changes as new data.

Managing with Test

• Ensure all tests are done
• Have a strong team.

Success for reviews

• The team leader is prepared, knows how what to check, and does their research.

Test Management

Roles and responsibilities

• Typical Roles are the testing team.

What does a test do?

• Ensure all criteria tests pass, especially through test codes.

Test Planning

• Understand - Test Data
• Identify - Root Cause
• Testing - Time.

Test activity planning for software

• Set and follow plan to the letter
• Work to all needs to do what most effectively follows goals set at test
• Testing objectives throughout all testing.

Test activity Results

• Review
• Implementation of requirements to the tests needed
• Analysis
• And documentation

Testing with Data

• Verify if tests can be used that all is correct
• Important - Is the understanding between all.

Three different Test cases

• Test that helps test environment
• Does a work product
• To test and make changes based on ethics.

This quiz involves understanding the benefits of ISTQB certification for software testers, assessing knowledge of testing, and applying testing principles. Questions cover cyclomatic complexity, data-driven testing, and coverage tools to evaluate software modules.