The University of Lahore
A “W4” Category University
Lecture 8
CHAPTER 2
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Chapter Contents
1. Commonly applied software development models.
2. Test levels
3. Test types
4. How maintenances influences the test process, levels
and types
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The University of Lahore
The University of Lahore
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Waterfall Model
1. Waterfall model is a model in which tasks are executed in sequential fashion.
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The University of Lahore
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REVIEW
Requirements (What is requirement?)
1. Carry out the preliminary study of the situation 2. Decide exactly what the problem is?
Feasibility Study
3. Cost analysis
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Analysis
Study the existing system in detail is called analysis.
1. Interview users of the current system
2. Read any manual or instructions which are in use
3. Observe the current system in operation
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Designing
1. Data capture forms 2. Type of user interface
3. Validations methods-how is input data going to be test?
4. Programs-if some new programs has to be written then they have to be designed at this stage
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Construction & Testing
1. Coding (any new program have to be written)
2. System testing. Test data is designed and the results are forecast
3. Acceptance testing. The users of the new system check it
4. user documentation is prepared
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Implementation - Conversion
1. File conversion
2. Software and hardware installation 3. System conversion
System Maintenance and Review
4. Keep watching on the new system
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Problems/Challenges associated with Waterfall Model
1. Testing tends to happen towards the end of the project
life cycle, so defects are detected close to the live
implementation date.
2. Difficult to carry out numerous alterations for a
particular phase.
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4. Partitioning of the project into different stages
makes it difficult to respond to changing customer
requirements.
5. Unrealistic to expect accurate requirements so early
in the project
Therefore, this model is only appropriate when
the requirements are well-understood
The changes will be limited during the design
process.
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Advantages of Waterfall Model
1. Most common
2. Simple to understand and use
3. Easy to manage
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V - Model
The V-model is a model that illustrates how testing activities (verification and validation) can be integrated into each phase of the life cycle.
3 Levels of V-Model
1. Procedure (What has to be done?) 2. Methods (How the tasks are to be
performed?)
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The V-Model is structured into four functional parts, called submodels.
Project Management (PM) tasks
1. The PM submodel states that the staff members should participate in all activities.
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Software/System Development (SD)
1. Develops the software/system
2. Big emphasis on Commercial Off The Shelf soft wares
3. COTS must be given special attention.
Quality Assurance (QA)
4. Access the product or software
5. Compares the product or software with the plans and requirements.
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Configuration Management (CM)
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V - Model
Test Level
“A group of test activities that are organized and managed
together in V-Model.”
Integration Testing Component Testing Acceptance Testing System Testing
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Component Testing
Searches for defects and verifies the functioning of software components (modules, programs, objects, classes etc) that are separately testable.
Integration Testing
Tests interfaces between components, interactions to different parts of a system such as OS, file system and hardware.
System Testing
Concerned with the behaviour of the whole system/product.
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Verification & Validation
Verification
1. Have you built the product right?
2. Does the product meet system specification?
Validation
3. Have you built the right product?
4. Does the product meet user expectations?
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A “W4” Category University
The University of Lahore
A “W4” Category University
The University of Lahore
A “W4” Category University
The University of Lahore
A “W4” Category University
The University of Lahore
A “W4” Category University
V - Model
Represent testing where system is validated Specifications or
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Comparisons
Waterfall Vs V-Model
Waterfall Model V-Model
the start of the next phase will occur at
the completion of the previous phase. development and testing processes will occur simultaneously to save the time as well as money.
the output of each phase will become
input to the next phase. verification we can also do the validations. we can't go back in the waterfall
model. We can design the test case for acceptance test when requirement phase is carried out and so on……
If any defect you can identify the risk,
