It 2012 13 Even II It 2 Marks It2251 Seqa 2marks

2 MARKS QUESTIONS & ANSWERS, Prepared by, P.Blessy Paul, AP/IT Dept

DEPARTMENT OF INFORMATION TECHNOLOGY

IT2251-SOFTWARE ENGINEERING AND QUALITY ASSURANCE

SEM/YEAR-04/02

UNIT-I

SOFTWARE PRODUCT AND PROCESS

1. What is software engineering .

Software Engineering is a discipline in which theories ,methods and tools are applied to develop professional software product.

2. Differentiate between Software Engineering and Computer Science.

Software Engineering

Computer Science

The software engineering is concerned with the practical problems of producing software.

The computer science deals with the theories and methods used by the computers and software systems.

Some knowledge of computer science is necessary for the software engineers to develop the software.

Elegant theories cannot be completely applicable to the software engineering when software solution to complex or real world problem has to be developed.

3. What is software process model.

The software process model can be defined as an abstract representation of process. The software process model consists of various process activities, role of people involved in process development and software product.

4. How to determine the costs in the software engineering.


The costs in the software engineering system depends upon- the type of software being developed and the software process being used.

5. How to create good software.

Satisfying the user requirement is not the only goal of good software. There some essential attributes of good software and those are,

i) Maintainability

ii) Usability

iii) Dependability

iv) Efficiency

6. What are challenges in software engineering.

The key challenges facing software engineering are:

Copying with legacy systems.

Heterogeneity challenge.

Delivery time challenge.

7. What are software characteristics?

Software development is a logical activity and therefore it is important to understand basic characteristics of software .Some important characteristics of software are,

• Software is engineered, not manufactured.

• Software does not wear out.

• Most software is custom built rather than being assembled from components.

8. What are goals/ objectives of software engineering?

♦ Satisfy user requirements.

♦ High reliability.

♦ Low maintence costs.


♦ Delivery on time

♦ Low production costs.

♦ High performance.

♦ Ease of reuse.

9. Define Verification and Validation.

Verification reprents the set of activities that are carried out to confirm the software correctly implements the specific functionality.

Validation reprents set of activities that ensure that the software that has been is satisfying the customer requirements.

10. What is system engineering?

System Engineering means designing, implementing, deploying and operating the systems which include hardware, software and people.

11. What are restraining factors for system model constructions?

♦ Assumptions

♦ Simplifications

♦ Limitations

♦ Constraints

♦ Preference

12. Define Computer based System.

The computer based system can be defined as “a set or an arrangement of elements that are organized to accomplish some predefined goal by processing information”

13. What are goals of business process Engineering.

♦ The goal of business Process Engineering is to define such an architectures using which information can be effectively used by the business.

♦ For satisfying business architecture and goals there are three different architectures that can be analyzed and designed these are,


♦ Data architecture

♦ Applications architecture.

♦ Technology infrastructure.

14. What are the goals of product engineering

• The goal of product engineering is to translate the customers demand working product.

• To achieve this goal architecture is built.

15. What is embedded system process.

The embedded system process is a process which works as a part of software model. Embedded system process run on a single processor or an integrated group of processors.

16. Distinguish between process and methods.

Software process can be defined as the structured set of activities that are required to develop the software system. Various activities under software process are.

Specification

Design and implementation

Validation

Evolution

Method is used mainly in object-oriented programming; the term method refers to a piece of code that is exclusively associated either with an class or a object.

17. Why software architecture is important in software process.

The software architecture gives the hierarchical structure of software components and their interactions .In software architecture the software model is designed and structure of that model is partitioned horizontally or vertically .This helps in implementing a quality software product.

18. What are phases encompassed in the RAD model.


Various phases in the RAD model are

Business modeling

Data modeling

Process modeling

Application generation

Testing and turnover

19. Which process model leads to software reuse? Why.

The object oriented model is used for the software reuse because –this model is based on the incremental development of the software product. This can be done in one or more iterations.

20. What does system engineering model accomplish?

System engineering is modeling process. it accomplishes following things.

♦ The process that needs a view of consideration is defined.

♦ Behavior of the system.

♦ Exogenous and endogenous input is defined.

♦ All linkages for understanding each view must be represented.


UNIT-II

SOFTWARE REQUIREMENTS

1. What are problems associated with requirements.

Requirements imprecision-

(1) Problems arise when requirements are not precisely stated.

(2) Ambiguous requirements may be interpreted in different ways by developers and users.

(3) Consider meaning of term ‘appropriate viewers’

(a) User intention-Special purpose viewer for each different document type.

(b) Developer interpretation-Provide a text viewer that shows the contents of the document.

Requirements completeness and consistency.

2. Define Feasibility studies.

A feasibility study is a study made to decide whether or not the proposed system is worthwhile.


3. What are the benefits of software prototyping?

• Prototype can serve as a basis for deriving system specification

• Working system becomes available as there is a closer match of prototype with actual system

• System can be maintained easily

• Development efforts may get reduced

• If any service is missing or confusing then that can be identified

4 . Write the advantages of Evolutionary prototyping

♦ Fast delivery of the working system

♦ User is involved while developing the system

♦ More useful system can be delivered

♦ Specifications design and implementation work in co-ordinate manner

5 . What are the problems occur in throw away prototyping

Developers may be pressurized to deliver throw away prototype as final system

The throw away prototype can be undocumented

Sometimes organizational quality standard may not be strictly applied

Changes made during the software development process may degrade the system structures.

6. State the analysis Modeling Approach

Analysis Modeling Approach

Structured approach

Object Oriented approach

The analysis is made on data and process in which data is transformed as spate entities

The analysis is made on the classes and interaction among them in order to meet the customer requirements.


Data objects are modeled in a way in which data attributes and their relationship is defined in structured approach.

Unified modeling language and unified process are used in object oriented modeling approach.

7. What are attributes

Attributes define properties of data object

Typically there are three types of attributes:

♦ Naming attributes: These attributes are used to name an instances of data object

♦ Descriptive attributes: These attributes are used to describe the characteristics or features of the data object

♦ Referential attribute: These are the attributes that are used in making reference to another instance in another table

8. Define cardinality and Modality

Cardinality in data modeling ,cardinality specifies how the number of occurrences of object is related to the number of occurrences of another objects.

9. Define data Dictionary

The data dictionary can be defined as an oranginised collection of all the data elements of the system with precise and rigorous definitions so that user and system analyst will have a common understanding of inputs ,outputs, components of stores and intermediate calculations.

10. Why SRS must be traceable ?What is traceability requirements

There may be chances of having new requirements during development of the software. Traceability is concerned with relationship between requirements their sources and the system design. Thus change in requirement is manageable if SRS is traceable.

11. Compare evolutionary prototyping and throw away prototyping

Evolutionary Prototype Throw away prototype


The principle objective of evolutionary model is to deliver the working system to the end user

The principle objective of throw away prototype is to validate or derive the system requirements

The process of development starts with well understood requirements.

The process of development starts with poorly understood requirements

It must be developed for the systems where the specifications cannot be developed in advance

The process away prototype is developed to reduce the requirement risks.

12. Compare functional and behavioral model

Functional model

Behavioral model

The functional model depicts all the essential functionalities of the system

The behavioral model represents how system behaves

The functional model is represented by data flow and control flow diagrams

The behavioral model is represented by state chart diagram

The DFDS can be represented by levels

The state diagram has some number of states and transitions

13. What is meant by software prototyping.

System prototyping us a rapid software development for validating the requirements .The use of system prototype is to help customers and developers to understand the system requirements.

14. Differentiate between data flow diagram and state transition diagram.

Data Flow diagram State Flow diagram Data flow diagram is graphical representation for representing the information flow and the transforms that are applied as data move from input to output

State transition diagram is a graphical representation for representing the behavior of a system by depicting its states and the events that cause the system, to change state.


The data flow diagram is a collection of process data store, flow of data.

The data flow diagrams are used to represent the system at any level of abstractions and the increasing levels are used to expose more and more functionalities in the system.

The state transition diagrams are typically drawn at single level .They intended to expose the overall behavior of the system.

15. Which style of prototyping is most appropriate when the requirements are not well understand.

A throw away prototyping approach has to be used when requirements are not well understood .Because in this approach there is a rough demonstrations of requirements and it can be discarded if not achieving the level of satisfaction.

16. How do we use the models that we create during requirements analysis.

Data, functional and behavioral requirements are modeled in various diagrammatic formats. Data model defines data objects attributes and relationship functional modeling indicates how data are transformed within a system Behavioral model shown the impact of events ,After creating these models they are further refined and analyzed for its completeness and competency.

17. What is requirement Engineering?

Requirement Engineering is the process of

Establishing the services that the customer requires from a system.

And the constraints under which it operates and is developed.

18.What are the types of non functional Requirements.

The classification of non functional requirements are

Product Requirements

Organizational Requirements

External Requirements.

19. State the uses of CSPEC?

How the software behaves when an event or signal is sensed.


Which processes are invoked as a consequences of the occurences of event.

20. What is the major distinction between user requirements and system Requirements?

The user requirements describe both the functional and non functional requirements in such a way that they are understandable by the users who donot have detailed technical knowledge.On the other hand the system requirements rae more detailed specifications of sytem functions,services and constraints than user requirements.


UNIT-III

ANALYSIS,DESIGN CONCEPT AND PRINCIPLES

1. What are elements of analyzing model.

The elements of analyzing model are,

• Data Dictionary

• Entity relationship diagram

• Data flow diagram

• State transition diagram

• Control specifications

• Process specifications.

2. State the Design principles.

• The design process should not suffer from “tunnel vision”

• The design should be traceable to the analysis model.

• The design should be structured to accommodate change.

• The design should exhibit uniformity and integration.

3. Define modular Design.


Modular design reduces complexity and helps in easier implementation .The parallel development of different parts of the system is possible due to modular design.

4. What are different types of cohesion?

Coincidentally Cohesion

Logically cohesion

Temporal cohesion

Procedural cohesion

Communicational cohesion

5. What are benefits of refactoring?

Benefits of refactoring are,

♦ The redundancy can be achieved

♦ Inefficient algorithms can be eliminated

♦ Poorly constructed

♦ Other design failures can be rectified.

6. Write advantages of Graphical User Interface.

♦ GUIs are easy to use .An inexperienced user can the system easily with the graphical user interface

♦ The user can switch from one task to another very easily .He can also be interact with many applications simultaneously.

♦ Fast and full screen interaction is possible with user.

7. Define Real time system

Real time system is software in which the correct functionalities of the system are dependent upon results produced by the system and the time at which these results are produced.

8.What are the real time software design.

Periodic Stimuli: These are the stimuli that occur at periodic time interval.

A periodic Stimuli: These are the stimuli that occur at unpredictable time interval


9. What are executive’s components of real time Executives?

The executive’s components are

Real time clock

Interrupt handler

Scheduler

Resource manager

Dispatcher

10. How Scheduling Strategies can be done.

The Scheduling Strategies can be done as

• Non preemptive scheduling

• Preemptive scheduling

• Various scheduling algorithms that can be used are shortest job fist, round robin, priority based scheduling.

11.State the guide lines for modular design

The guideline modular design are ,

Achieve the functional independence

High level of cohesion should be achieved

There should be minimum number of coupling.

12. How do you evaluate user interface

The user interface can be evaluated by accessing the usability of interface and checking that it meets the user requirements.

After preparing the preliminary design a first level prototype is created.This prototype is evalusted by the user.

The a formal technical review is conducted.


The feedback of both the above mentioned reviews is given to the designer to make appropriate design modifications.

The evaluation cycle is continued no further modifications are suggested in the interface design.

13. List out the Design concepts?

Abstraction

Modularity

Architecture

Refinement

Pattern

Information Hiding

Functional Independence

Refactoring

Design classes

14.What are Data Acquistion system?

It is responsible to acquire the data for processing.In data acquistion system there are two major activities –Collection of data from sensors and Processing of collected data.The producer process is responsible for collecting the data and consumer process is responsible for processing of process. The circular or ring buffer is used to store the collected data.

15.Brief the importance of uer Interface?

An experienced user can use the system easily with the user Interface.

The user can switch from one task to another very easily.He can also interact with many applications simultaneously.the application information remains visible in its own window.

Fast and full screen interaction is possible with user.

16.What is the work product of software design process and who does it>


The work product of software design is the design specification.This specification consits of design models that describe data,architecture,interfaces and components.Software Engineers can do it but while designing the complex sytems specialized system engineers are required.

17.Name the three levels of abstraction,which are in practice for the design?

There are three levels of abstractions.

Highest level of abstraction

Lower level of abstraction

Lowest level of abstraction.

In the highest level the solution is stated in broader terms using language of problem environment.

In the lower level more procedural orientation is taken.

In the lowest level the solution is stated in such a manner that we get the implementation of the solution.

18.What are the types of interface design?

User Interface

External interface to other systems,network and devices.

Internal interfaces betweeen various design components.

19.Why it is necessary to design the system architecture before specifications are completed?

The system architecture define sthe role of hardware,software,people,database procedures and other sytem elements.Designing of system architecture will help the developer to understand the system as awhole.Hence system Architecture must be built before specifications are completed.

20.If a module has logical cohesion what kind of coupling is this module likely to have with others?

When a module that performs a tasks that are logically related with each other is called logically cohesive.For such module content coupling can be suitable for coupling with other modules.The content is a kind of coupling when one module makes use of data or control information maintained in other module.


UNIT-IV

TESTING

1.Define Software Testing?

Software Testing is a critical element of software quality assurance and represents the ultimate review of specifiaction,design and coding.

2. What are the objectives of testing?

Testing is a process of executing a program with the intend of finding an error.

A good test case is one that has high probability of finding an undiscovered error.

A successful test is one that uncovers an as yet undiscovered error.

3.What are the principles of testing?

All tests should be traceable to customer requirements.

Tests should be planned long before tesing begins.

Testing should begin in the small and progress towards testing in the large.

Exhaustive testing is not possible.

To be most effective tesing should be conducted by an independent third party.

4. What are the levels of testing?

The testing can be typically carried out into two levels.

Component Testing:


In component testing individual components are tested.It is the responsibility of component developer to carry out this kind of tesing.These tests are derived from developers experience.

System Testing:

In system testing the testing of group of components integrated to create a system.It is the responsibility of an independent testing team to carry out this kind of testing.These tests are based on system specification.

5. What is Black Box testing?

It is also called as behavioral testing.This method focus on the functional requirements of the software.Tests cases are derived that fully exercise all functional requirements.It is not alternative to whitebox testing and it uncovers different class of errors than white box testing.

6. Why to perform black box testing?

Black box testing uncovers following types of errors

Incorrect or missing function

Interface errors

Errors in datastructures

Performance Errors

Initialization or termination errors

7. What is L9 Orthogonal array?

This array is used to generate the test cases.This array has a balancing property.That means the testing can be done uniformly by executing the test cases generated by the L9 Orthogonal array.

8. Define driver and stub?

Driver is a program that accepts the test data and prints the relevant results.

Stub is a subprogram that uses the module interfaces and performs the minimal data manipulation if required.

9.Write the drawbacks of big bang approach?


It is hard to debug.

It is not easy to isolate errors while testing.

It is not easy to validate test results.

After performing testing ,it is impossible to form an integrated system.

10.What are the different classes of test cases involved in regression testing?

Representative sample of existing test cases is used to exercise all software functions.

Additional test cases focusing software functions likely to be effected by the change.

Test cases that focus on the changed software components.

11. What are the benefits of smoke testing?

Integration risk is minimized.

The quality of the end product is improved.

Error diagnosis and corrections are simplified.

Assessment of progress is easy.

12.What are the types of acceptance testing?

The types of acceptance testing are

Alpha test:It is attesting in which the version of complete software is tested by the customer under the supervision of a developer.This testing is performed at a developers site.

Beta Test: It is a testing in which the version of software is tested by the customer without the developer being present. This testing is performed at customers site.The enduser records the problem and rep[ort them to developer.The developer then makes the appropriate modification.

13. What are the various types of system tests?

The various types of system tests are

Recovery Testing

Security Testing


Stress Testing

Performance Testing.

14.State the guidelines of debugging?

Debugging can be effectively carried out by mental analysis.

Use debugging tool only if no alternative is present.

If one bug occurs in one area of code then there are chances of occurrence of more bugs.

There are chances of introducing new errors on correction of older ones.

15.What is partial Integartion testing?

Partial Integartion testing verifies correct data movement from one external system to another.

For instance:If there is one system that brings data from single external system and then sends the data to several other external system.Then partial test of this system would be to tset whether the data can be sent to one of the external systems.

16.Define debugging?

It is aprocess of removal of a defect.It occurs as a consequences of successful testing.

17.Define stress testing?

It determines breakpoint of a system to establish maximum service lervel.

In stress testing the system is executed in a manner bthat demands resources in abnormal quantity,frequency or volume.

A variation of stress testing is a technique called sensitivity testing.

It is testing in which it is tried to uncover data from a large class of valid data that may cause instability or improper processing.

18.Distinguish between Black box and white box testing?

S.No Black box testing White box testing 1. It is called behavioral Testing It is called glass box testing 2 It examines some fundamental aspect The procedural details,all the logical paths,all


of the system with little regard for internal logical structure of the software

the internal datastructures are closely examined.

3. During black box testing the program cannot be tested 100 percent.

It lead to test the program thoroughly.

4 This type of testing is suitable for large projects.

This type of testing is suitable for small projects

19.Distinguish among Error,Fault,Failure.

Error: It is a state that can lead to a system behavior that is unexpected by the system user.

Fault: It is a characteristic of a software system that can lead to system error.\

Failure: It is an event that occurs at some point in time when the system doesnot deliver a service as per users expectations.

20.What is the objective of unit testing?

The objective of unit testing is to test individual components independently to ensure their quality.Thus the focus is to uncovers the errors in design and implementation.

UNIT-V

SOFTWARE QUALITY ASSURANCE

1.Define software quality?

Software quality can be defined as “the conformance to explicitly stated functional and performance requirements, explicitly documented development standards, and implicit characteristics that are expected for all professionally developed software”.

2. Define quality assurance?


It is planned and systematic activities necessary to provide a high degree of confidence in the quality of a product. It provides quality assessment of the quality controlled activities and determines the validity of the data or procedure for determining quality.

3. Why software standard is important?

1. Use of software standards by the company is useful in avoiding the past mistakes. The standard helps in capturing the necessary and important things that are required for development of software.

2. The standards provide the solid framework for quality assurance processes.

3. The standard helps the next person to continue previous person’s work without breaking any continuity. Thus if a new employee joins the ongoing software project then his learning efforts get reduced due to the software standards.

4. What are the types of documentation standards?

There are three types of documentation standards

1 Documentation Process standard: It defines the standard processes that needs to be executed.

2 Document standards: It defines the format of the document.

3. Document Interchange standards: It ensures that all the copies of the documents are as

per the standard.

5.Write some quality attributes that must be required during quality planning?

Adaptability

Complexity

Efficiency

Learnability

Reliability

Reusability

Robustness

Safety

Security


Understandability

6. What is software Review?

The software review is conducted by the group of people.This group checks whether or not the software getting developed is as per the quality standards.If any variations are presented from the standard then software reviewers note them and are informed to the project manager.

7. What are the various types of review?

Program Inspection

Progress reviews

Quality Reviews

8.What are the types of software attributes?

There are two types of software attributes.

1.External Attribute:

External Attributes are those attributes that can be seen by the user as well as by the developer.These attributes depicts the basic characteristics of qualitative software.

2.Internal Attributes:

Internal Attributes are those attributes that can be measured directly.

9.Write the conditions for the relationship between the external and internal software attributes?

The internal attribute must be measured correctly.

The relationship must be present between the measured internal attribute and the desired external attribute.

The relationship must be validated and must be formulated.

10..What are the various steps conduct for product measurement?

Choose the measurement.

Select the components for measurement

Measure the component characteristics


Identify anomalous component

Analyse anomalous component

11. Difference between the dynamic metric and static metric?

Dynamic Metric Static Metric It is collected during the program execution

It is collected during design,coding or documentation phase.

It helps to compute the efficiency and reliability of program

It helps to access the complexity,understandablity and maintainability of software system

It can have direct relationship with quality attribute.

It can have indirect relationship with quality attribute

12. What are various static product metrics?

The various static product metrics are-

Fan in and fan out

Length of code

Length of identifiers

Cyclomatic complexity

Depth of conditional nesting

Fog index.

13. Define fog Index?

It represents total number of words and sentences in the software document.If fog index high then that means the document is lengthy and hard to understand.

14. Define Process improvement?

Process improvement means understanding the existing process and changing these processes to increase the product quality to reduce the cost and/or to reduce the development time inorder to accelerate the project.

15.What are the process attributes focusing on the concept of process improvement?


Understandablity

Visibility

Reliability

Supportability

Robustness

Acceptability

Rapidity

Maintainability

16. What are the stages involved in Process improvement?

Process Improvemnet:

Current project attributes are measured.then identify the process that needs to be improved.

Process Analysis:

o The identified process is analyzed to obtain the bottlenecks and weaknesses.

Process Change:

After analysis phase some processed need to get changed.In this phase the required changes are incorporated in the process.

17. What are the four main factors that affect the product?

The four main factors that affect the product are

Process quality

Development Technology

People skills

Project cost and schedule.

18. Write the classification of process?

Informal processes


Managed Processes

Methodical Processes

Improving Processes

19.Define Ethnography?

Ethnography is a technique of understanding social and organizational requirements.The ethnographic studies help to understand the software development process. This analysis helps in finding the complexities present in the system.

20.Define software configuration management?

It is a set of activities carried out for identifying,organizing and controlling changes throughout the lifecycle of computer software.

21.What are the methods used in SCM repository?

Data Integrity

Information sharing

Mthodolgy enforcement

Tool Integartion

Data Integartion

Document standardization.

22.Write the features of SCM?

Versioning

Dependency tracking and change management

Configuration Management.

Requirement Tracing

Audit trials

23.Write the standards of SCM?

AECL CE-1001-STD REV.2

BS 7738-1


IEEE 1042-1987

ISO/IEC TR 18018:2010

24.Write the estimation Techniques?

Algorithmic cost modeling

Expert Judgement

Estimation by analogy

Parinsons law

Pricing to win

25. What are the parameters for software configuration?

Identifiaction

Version control

Change Control

Configuration audit.

Status reporting.

Documents

It 2012 13 Even II It 2 Marks It2251 Seqa 2marks