Chap 1: Introduction to software engineering and process models : Important Questions & Answers

 Q1. Define software.

Answer: Software is a set of instructions to acquire inputs and to process them to produce desired output.

Q2. Differentiate between software and hardware.

Answer:

Software	Hardware
It is developed or engineered.	It is manufactured.
Not prone to environmental conditions.	Prone to environmental conditions.
Cannot be replaced by spare parts.	Can be replaced by spare parts.
It is untouchable.	It can be touched.
It is invaluable.	It has no value without software in it.

Q3. Differentiate between system software and application software.

Answer:

System Software	Application Software
Concerned with efficient management of computer system.	Concerned with solution of some problem.
It is machine dependent.	It is machine independent.
We can make them portable using bootstrapping.	We can make them portable using cross compiler.
Related to architecture of machine.	Related to knowledge of language and environment.
Example: Assembler, loader, compiler.	Example: Paint, photoshop, etc.

Q4.  What are different types of process flows.

Answer: There are 4 different types of process flows:

1) Linear process flow: Activities are executed in a sequence.

2) Iterative process flow: One or more activities are repeated before processing to next.

3) Evolutionary process flow: Activities are executed in cyclical manner.

4) Parallel process flow : Activities are executed in parallel with other.

Q5.  Explain layered technology of software engineering.

Answer: The layers of software are as follows:

1. Quality focus: It is the primary goal of any software process.

2. Software process: It consists of predictable steps to create timely and high quality product. 

examples: Producing models, documents, establishing milestones,etc.

3. Software engineering methods: Methods are organized way of producing the software. Process to follow, notations to use, rules & design guidelines, etc.

4. Tools : They provide support for process and methods. CASE tools are specially deigned to support the acitivities. Example: Visual studio .NET is a code generation tool.

Q6. What is the need of feasibility study ? 

Answer: We need feasibility study due to following reasons:

1. It determines potential of existing system.

2. It finds problems of existing system.

3. It finds technology to solve the problems.

4. It avoids costly repairs.

Q7. What are types of feasibility study.

Answer: 

There are three types of feasibility study:

1) Technical feasibility: It determines available hardware, software, operating time,etc. of existing system and determines new requirements for proposed system.

2) Operational feasibility: It determines suitability of system in terms of human, organizational and political aspects like ease of operation, requirement of training,etc.

3) Economical feasibility: Here It finds total costs and all benefits as well as expected savings of proposed system like onetime and recurring costs.

Q8. What does radius & angle imply in spiral model?

Answer: In spiral model the radius implies the cumulative cost incurred in finishing steps so far and angular dimensions represent the progress made in completing each cycle.

Q9. Give advantages and disadvantages of incremental model.

Answer: Advantages are as follows:

1. It is faster than waterfall model.

2. It requires less number of staff.

3. Due to iterations it has more functions.

Disadvantages are as follows:

1. It may require large space in memory.

2. It may produce low quality software.

3. It's delivery date could not be decided.

Q10. Give disadvantages of RAD model.

Answer:

Disadvantages:

1. High dependency on on modelling skills increasing the project cost.

2. Not suitable for high technical risk projects.

3. Without interaction with customers, the project may collapse.

Q11. Give advantages and drawbacks of RUP.

Answer: 

Advantages :

1. Main focus is on quality.

2. Identifies high risk areas.

3. Allows change in requirements as project evolves.

Drawbacks:

1. Fails to provide clear implementation guidelines.

2. Leaves tailoring entirely to user.