1.2.3 Software Development

Question 1

What is the purpose of an ICT development project

Answer 1

• To create an application system, which is a combination of software and hardware that meets the needs of a given set of users or purposes.

Question 2

What are reasons to commision a new system

Answer 2

• Company expansion
• Old systems being too slow compared to modern alternatives
• Lack of support for old software
• A desire to capitalise on new technologies

Question 3

What does a new ICT system require also apart from programmers

Answer 3

• business experts
• analysts
• project managers
• testers
• technical authors
• marketers

Question 4

What are Stakeholders

Answer 4

• A stakeholders is someone, or a group of people, with a vested interest in the new system being built.
• They can be passive stakeholders, which means they won’t be involved in production
• or active skakeholders who play a part in system being built.

Question 5

What are the main categories for stakeholders

Answer 5

• Users
• Programmers/dvelopers
• Project Managers
• System Analysts

Question 6

What are the users

Answer 6

• Are not the same as the client.
• The client requires the new system to be built and the user will be the one interacting with it.
• It is crucial to consider the users, as they are the people who will be interacting with the system on a daily basis.
• If the system doesn’t meet their needs, it will fail

Question 7

What are the Programmers/Developers

Answer 7

• Are the people building the system.
• They take information passed on by the systems analysts and use it to develop the system. They will have specialist knowledge of several programming languages and can make informed decisions to which is most sutiable to develop the system.
• They rarely have direct involvement in the analysis or design but have vested interest in the success of the project.

Question 8

What are the Project Managers

Answer 8

• Have a critical role in the project. It is their responsibiliy to monitor progress and allocate resources to the project.
• There is normally a project manager on both the client side and the developers side. These project managers work closely together to avoid any bad surprises showing up.
• In order for the project managers to plan project successfully, they need to understand how well their teams work and what skills they have and to ensure they know as much as possible about their team. That way they can monitor the progress

Question 9

What are System Analysts

Answer 9

• Systems analysts find out exactly what the client wants.
• Analysts have to use their own experience. They are responsible for investigating the organisation’s objectives and producing the requirements specification.
• They will also suggest possible implementation methods for the proposed project.
• They will document the existing system so can be clearly understood by the system designer and programmer.

Question 10

What is Problem Definition

Answer 10

• Before starting the cycle, we need to understand what the problems with the current system are and what problems the new system will solve.
• Once the problem has been diagnosed, the scope of the project can be laid out.
• Unbounded projects are guaranteed to fail, as there is no way to differentiate what the customer required at the start and what they require 6 months down the line
• The problem definition phase documents the process of identifying what problems exist in a client’s current system or defining what problems with their existing system or software to help them expand their company

Question 11

What is a Feasibility study

Answer 11

• A feasibility study establishes whether or not the project can be done given the scope laid out during problem definition.
• Also it considers whether it is desirable for the development company to proceed with the project.
• A number of factors should be considered on deciding how feasible the new system will be: economic, time, technical, political, legal

Question 12

What is Economic Feasibility

Answer 12

• A project has a specific budget, which must include all the costs of the project, including
  
  • Software Licenses
  • Hardware
  • Human Resources/Wage
• Human costs are the most variable and account for majority of the project.
• Economic Feasibility considers the overall budget and costs. It then decides if enough profit can be made to make the project worth doing. A good reputation may lead to future projects, so it’s worth maintaining

Question 13

What is Time Feasibility

Answer 13

• Late projects result in going over budget because of the cost of developer’s wages.
• It is important that projects are delivered on time, as the developing company will make a negative impression.
• Sometimes it is even more critical, as the client could have pressing business reasons for a project to be delivered by a certain date.
• Once the estimated length of development has been calculated, it is compared with the client’s deadline. If it can be done in the given time frame, the project can go ahead

Question 14

What is Technical Feasibility

Answer 14

• Can the project be done with the technical resources available?
• Some requirements may not be possible or feasible with current technology.
• However, what is more likely to cause problems is if the development team does not have the technical skills needed to satisfy the requirements

Question 15

What is Political Feasibility

Answer 15

• Projects can sometimes have issues that may go against the beliefs of certain groups of people.
• When these projects go wrong, the national media will report on it and show the development company negatively.
• The development company needs to decide if the positives outweigh the negative publicity.

Question 16

What is Legal Feasibility

Answer 16

• Legal feasibility helps decide whether the project will be able to comply with all of the laws that may affect it in the countries where it will be released.
• File sharing software can be against the law, companies producing or facilitating illegal activity are sued
• Legal feasibility needs to be taken seriously, as the effects can be damaging for the client and the developing company.
• Also some countries might ban the use of software completely if it doesnt meet the basic legal requirements.

Question 17

What are the different fact-finding methods

Answer 17

• Observation
• Questionnaire
• Document Collecting
• Interview/ Meeting

Question 18

What is the Observation Fact-Fnding methods

Answer 18

• Analyst shadows employees of the customer for a period of time, making notes on how they do their job
• Observe employees in their natural environments to see how their business works.

Question 19

What are the advantages and disadvantages of the Observation Fact-Finding method

Answer 19

• Advantages:
  
  • Pick up parts that aren’t immediately obvious to the client
  • Confirm information gathered by other fact-finding methods
• Disadvantages:
  
  • Some may feel threatened being watched
  • No guarantee subtle parts will show up

Question 20

What is the Questionnaire Fact-Finding method

Answer 20

• Designing questionnaires requires knowledge of the system built and sent out to people
• Prior knowledge is essential so questions can be targeted.

Question 21

What are the advantages and disadvantages of the Questionnaire Fact-Finding method

Answer 21

• Advantages:
  
  • Can be given to a large number of people
  • Get large number of different responses
  • Targeted responses - large amounts of data analysed + quantitative results
• Disadvantages:
  
  • Hard to create/ design questions + responses
  • Not all questionnaires are completed
  • Free responses = time consuming to analyse + many opinions to consider

Question 22

What is the Document Collecting Fact-Finding method

Answer 22

• Analyst gathers any business documents that relate to the new system to be built.
• Orders, invoices, financial records, documents in regular use.
• Key elements can be inferred:
  
  • The data they use/ what will need to be stored
  • The analyst gets a good understanding of the business process/ following trails of documents and flow of data from start to finish.

Question 23

What are the advantages and disadvantages of the Document Collecting Fact-Finding methods

Answer 23

• Advantages:
  
  • Documents are reliable/ show data stored in the system
  • Document trails help support analyst’s picture of business processes
• Disadvantages:
  
  • Documents give limited view/ doesn’t say how they were created
  • May contain sensitive info. Restrictions on viewing them

Question 24

What is the Interview/ Meeting Fact-Finding Method

Answer 24

• Most analysts start - select key stakeholders and ask them targeted questions of the current and new system.
• Lots of info can be gathered in short space of time. Analyst can ask for clarification.

Question 25

What are the Advantages and Disadvantages of the Interview/ Meeting Fact-Finding Method

Answer 25

• Advantages:
  
  • Large amounts of info gathered and analyst can respond to queries
  • Interviews produce detailed responses
• Disadvantages:
  
  • Time consuming - few people only
  • May not be fully truthful - verification needed.

Question 26

What are Requirements

Answer 26

• A requirement is a specific feature of the new system and is recorded in a document called the requirements specification
• Requirements must be measurable. Met/ not met. Must be interpreted correctly may lead to conflict and problems.

Question 27

What are Interface Requirements

Answer 27

• The interface of the end user interacts with it. Interface Requirements depend on the end user + complexity of the new system.
• The developers are interested if the interface is considered sutiable by the end user.
• Examples: hardware is durable, software accessible to a beginner

Question 28

What are Functional Requirements

Answer 28

• Functional Requirements detail what the system will do and key features it will have
• Examples: Microsoft word, auto correction, word count, spell check
• The key is what they do when the user clicks on them. Focus is what the features need to achieve in order to be successful.

Question 29

What are performance Requirements

Answer 29

• Examples: Response times and throughput.
• Have to be specific. Bounded means a reasonable maximum time agreed by both sides.
• Real time must be clear, realistic and measurable.

Question 30

What is the design phase

Answer 30

• Process of taking the requirements of the new system and deciding what it will look like, how it will store and process data.
• The design phase can only go ahead once the requirements specification has been completed.
• The design includes a number of areas:
  
  • Hardware and software choices
  • Data
  • Output Design

Question 31

What is Input in the design phase

Answer 31

• Also known as the interface design.
• Shows how info will be input into the new system and how it will be displayed after processing
• Doesnt describe how info is processed, nor functional requirements except interaction.

Question 32

What is output in Design phase

Answer 32

• Similar to input design. Look at what triggers the output. (triggered by something inputted
• Triggers include entering new data, clicking on buttons.

Question 33

What is Data Structure Design in the design phase

Answer 33

Dictates what needs to be stored and how data is organised.

Question 34

What is the Build phase in the systems development lifecycle

Answer 34

• Development is the planning, writing and alpha testing of the software. Includes user and technical documentation.
• Usually longest part of creating new applications.

Question 35

Why is it needed to test

Answer 35

• Untested or poorly tested code tends to result in ustable applications and incorrect output
• Leads to dissatisfied clients

Question 36

What is White box testing

Answer 36

• Evaluates the code and internal structure of the program.
• Requires knowledge on how the code was developed. IF statements create new paths and all paths must be tested in order to make sure they run as expected.

Question 37

What are Unit tests

Answer 37

• Developers use unit tests to ensure the code works as expected. Runs with various inputs. Allow fast regression of existing code. Should use valid, invalid and extreme data to ensure expected outcome
• Good for developers to do alpha testing in a systematic way and test code throughout lifetime. Most run tests at the end of day and following day check for errors.

Question 38

What is Black box testing

Answer 38

• Don’t have knowledge of the code and are testing the functionality of the program based on the requirements specification.
• Take valid, invalid and extreme data and compare output to expected output.
• Not interested in which paths were followed. Just interested if the code does what it is expected to do.
• Commonly done by people who aren’t directly involved - systematic manner

Question 39

What is the alpha build

Answer 39

• Alpha builds are not stable and lack functionality in all circumstances. Carried by in house testing team.
• Important that alpha build is not given to client - they may feel this is the quality they will recieve.

Question 40

What is the Beta Build

Answer 40

• More complete and stable than alpha build.
• Since all main functionality has been tested - may contain bugs and problems
• More stable to give to the client for testing. The intended user tests the system and faults are returned for correcting

Question 41

What is Acceptance Testing

Answer 41

• Last testing phase - occurs before client agrees to pay for the final system
• The goal of acceptance testing is for the customer to ensure that the developer has produced a product that meets the requirements specification.
• This testing marks the end of the contract. If successful the development company will be paid.

Question 42

What are the types of documentation

Answer 42

• User documentation
• Technical documentation

Question 43

What is user documentation

Answer 43

• Should be a full set of documentation after the user has completed training
• Will be used for users who start to use the system after intial launch. Should be carefully targeted to users and their needs and should be straightforward
• Can include:
  
  • Step by step guides/ tutorials
  • Installation guide
  • Reference Manual
  • Error messages
  • Frequently asked questions
  • Glossary

Question 44

What is Technical Documentation

Answer 44

• If the new system is a bespoke product, there needs to be a person in the company who can ensure that it runs smoothly once it has been implemented
• Ensures system is set up correctly and allow smooth performance.
• Technical documentation includes
  
  • Any form of diagrams used in analysis and design
  • The data structure
  • Source code
  • Hardware and Software requirements
  • Configuration guide and options

Question 45

What is the Waterfall Model Methodology

Answer 45

• Initially used in manufacturing and engineering - products created are hardware not software.
• Stages are arranged in order - each stage cascades down to the next. Each step has an output
• Each stage ends with a deliverable document - produced to inform about the next stage.
• Can be shown to clients/ internally. Important they are accurate and detailed. (Different teams)
• Testing of deliverables after every stage. Make sure they meet overall requirements. Nothing omitted.

Question 46

What are the advantages of the Waterfall Methodology (5)

Answer 46

• Self contained steps are easy to manage
• Model forced developers to consider the requirements thoroughly rather than programming straight away
• Good for managing large groups of developers working in parallel
• Detailed thorough design reduces mistakes later
• Simple and easy to understand - attractive to clients.

Question 47

What are the disadvantages of the Waterfall model Methodology (3)

Answer 47

• Requirement changes mean going back to earlier phases that are complete - costs time and money
• Lack of customer involvement after analysis means issues arent highlighted until evaluation
• Difficult for programmers to understand requirements at the start. Projects evolve and they grow to understand the area. Problem amplified by time - once project is complted - requirements have changed drastically.

Question 48

What is the Spiral Model Methodology

Answer 48

• Less linear and constrained as other models. A reduced number of stages are visited and revisted.
• This approach is iterative and each completed cycle is an interation
• Development begins with intial feasibility study and analysis. Possible solution is designed to meet user requirements. Design is implemented in the form of a prototype (rough partially incomplete version of final product.)
• Shown to client, evaluates (functionality improved added or improved). Stages are then repeated by improving prototype until final product.

Question 49

What are the advantages of the Spiral Model Methodology (3)

Answer 49

• Successful in small and large groups + good choice if requirements are to change as project develops. Ideal for software engineers
• Prototypes make it better at adapting to unforseen circumstances better for changing requirements and experience (time, money, what needs to be done) and issues are highlighted quickly to what the customer wants
• Changes are easily incorporated by feedback.

Question 50

What are the disadvantages of the Spiral Model Methodology (3)

Answer 50

• It takes time to develop prototypes and get feedback, longer to get the product to customer.Costs more to develop
• No regular deliverables, deadlines can be difficult can fall behind without proper management
• Requirements stage may not be completed initially so problems cant be solved by adapting the prototype.

Question 51

What is the Rapid Application Development (RAD)

Answer 51

• Essentially a much quicker version of the spiral model. Once the users requirements have been ascertained through analysis, a modular design is drawn up.
• Development is entirely focused on prototyping and re-prototyping until the final product is created
• The prototypes must be re-used for RAD to work, as it relies on repurposing and developing the existing prototype to create the next one.
• RAD model breaks the analysis, design, implementation and testing stages into cycles titled business modelling, data modelling, process modelling, application generation and turnover.

Question 52

What are the different sections of RAD and what do they mean

Answer 52

• Business Modelling - The business model describes the flow of information around the system using flow diagrams and flowcharts
• Data Modelling - Results of business modelling are analysed and used to produce datasets or objects that are needed for the system to function
• Process Modelling - Descriptions added to data objects whether data is added, edited or deleted.
• Application Generation - The actual system is created by combining the process and data models to create a prototype
• Turnover - The prototype is tested at the end of each cycle. More testing required when modules are linked

Question 53

What are the Advantages of RAD (3)

Answer 53

• RAD has a heavy focus on modular design because modules can be created in parallel by separate teams and combined together to create prototypes quickly.
• Encourages collaboration between the developers and client. Constant client feedback on previous prototype is obtained in order to develop next prototype. Able to see working versions from early on - feel engaged any changing requirements can be incorporated in next prototype. Flexible and adaptable
• New requirements quickly taken into account.

Question 54

What are the disadvantages of RAD (4)

Answer 54

• Can’t be used for smaller projects. Not all applications are compatible with RAD
• If developers arent committed delivering on time (fail) and requires highly skilled developers/designers
• Big problems may be encountered later due to little planning in the beginning.
• Also problem if project can’t be divided into modules - not possible to make prototypes
• Reliance of modularisation means RAD development may require more developers to maintain speed

Question 55

Why are Agile techniques focus on more and why is it different from the rest

Answer 55

• Agile techniques value collaboration and people over processes and tools. Teams are trusted to organise themselves with focus on regular meetings rather than documentation heavy approach.and giving them tools/resources they need
• Spend more time meeting with client - spend more time producing software rather than detailed documentation - prefer to be judged on how software works - well written software

Question 56

What are the different ways Agile Methodology can be implemented

Answer 56

• Extreme programming emphasises 4 areas of Agile Development. Communication, simplicity, feedback and courage. Simplicity - adopt most straightfoward solution. Opportunities for regular feedback are built in the development process. Paired programming - 1 develops while other gives advice
• Scrum Programmers: focus on regular iterations to create functional prototypes quickly. Focus on having fixed - length iterations called sprints. Worked on by several teams - working on different functionality and hold meetings.

Question 57

Advantages to Agile Methodology (3)

Answer 57

• Small multitasking groups make the team flexible to changing requirements - more effective in rapidly changing environment.
• Better written software without focussing on documentation. Produced quickly.
• Regular feedback

Question 58

What are disadvantages to Agile Methodology (2)

Answer 58

• Only sutiable for smaller development teams
• Lack of documentation and specific deadlines leads to problems

Question 59

What is the implementation stage

Answer 59

• Implemetation stage (bespoke systems) is the process of installing the new system at the client site and putting it into use. Occurs after the software and documentation have been produced.
• There are a number of ways to manage implementation of the new system
  
  • Direct Changeover
  • Phased Changeover
  • Pilot Changeover
  • Parallel Changeover

Question 60

What is direct changeover

Answer 60

• Simplest option but dangerous. Only be used if there is no existing system or the old system is broken.
• Swapping the system from old to new - could mean loss of productivity

Question 61

What is phased changeover

Answer 61

• Big projects are often split into modules. These can then be installed in a staggered timetable, allowing each to be tested and bugs addressed

Question 62

What is parallel changeover

Answer 62

• Best for a system that cant afford to fail.
• 2 systems run at the same time, casuing a duplication of data and workload. If new system fails, there is no effect on productivity.

Question 63

What is pilot changeover

Answer 63

• Large companies may trial a new system in a small number of areas, therefore mitigating the risk of failure, but still experiencing full integration of the new system in a localised area.
• Best for a business site - few shops run new system.

Question 64

What is Maintenance phase

Answer 64

• After implementation, a system is handed to the customer and then enters maintenace. Covers:
  
  • Fixing problems and adding functionality
• The customer expects 1 of 2 maintenance arrangements:
  
  • Developer will fix any problems for a period of time after product is released. Rolling maintenace contract or upfront payment
  • The develop will charge for every fix that is produced “pay as you go”

Question 65

Why is Maintenace soo expensive and what are the 3 approaches to providing maintenance

Answer 65

• It requires developers and a team to support the product. Bugs can be costly to fix
• Adaptive, Corrective and perfective

Question 66

What is Adaptive Maintenance

Answer 66

• Development company fixes bugs and adds extra functionality to the system.
• New features tend to be added based on external needs, complying with laws requires adaptive changes

Question 67

What is corrective maintenance

Answer 67

• Simply fixes problems as they arise to ensure the system closely matches the original specification.
• To fix problems without adding extra functionality.

Question 68

What is perfective maintenance

Answer 68

• Maintenance performes with the aim of achieving a perfect system. Necessary to fix all the problems. If there are changed requirements, the developers must provide updates to implement them
• Perfective maintenance is expensive and time consuming. Should only be used on small systems or critical systems

Question 69

What is evaluation

Answer 69

• Very important as it allows the development company and the client to decide whether the project was successful
• Evaluation = important to clients to make sure they are buying exactly what was specified in the requirements specification. Determines whether developers will be paid.
• There are a number of factors considered before the system is a success:
  
  • Requirements, Performance, Usability, Robustness and cost

Question 70

What is the factors of evaluation

Answer 70

• Requirements: Does it meet the functionality set out in the requirements specification. Each requirement must be objective and measurable
• Performance: Does it respond in a timely manner. Processes given a time frame or progress bars
• Usability: Software is useable by end users. Skill level and nature of solution
• Robustness: Crashes and bugs
• Cost: Budget. Over budget - usually unsuccessful

Question 71

1. What is an algorithm
2. Why may algorithms be used in
3. What is the difference between flowchart and pseudocode
4. What are the different shapes in flowcharts

Answer 71

• An algorith is a sequence of steps designed to perform a specific task
• Constructed to describe an operation of a complete system or a part of it
• Flowcharts - shows a series of steps in a diagram form. Pseudocode - text-based
• Diamond - decision, Rectangle - process, Oval - terminal, Input/Output - parallelogram. Rectangle with lines- subroutines

Question 72

What are the different program development techniques

Answer 72

• Incremental Development
• Iterative Developement
• Prototyping

Question 73

What is Incremental Development

Answer 73

• The entire system is designed before being split into separate modules or subsystems. Modules are programmed, designed tested one after another and added to the xisting release

Question 74

What are the Advantages of Incremental Development

Answer 74

• Software generated quickly - more feedback. More flexible and react better to changing requirements.
• Development is carried out by specialists, modules can be created by different teams. Can be written in different programming languages. Less likely to fail
• Also encourages thorough testing.

Question 75

What are the disadvantages of Incremental Development

Answer 75

• In order to be subdivided a problem must be well understood and major requiremnets well defined
• Extensive integration testing required- ensure modules work together

Question 76

What is Iterative Development

Answer 76

• Deliver a fully working product up front but build on functionality with every release.

Question 77

What is the advantages of Iterative Development

Answer 77

• Customers can experience system from an early stage of development and provide feedback on changes to be made. Works well for large projects where requirements are understood.

Question 78

What is the disadvantages of Iterative Development

Answer 78

• Projects can suffer if requirements arent substantively met by the initial release, after this the focus is refining existing functionality rather than adding new areas.

Question 79

What is prototyping

Answer 79

• Seeks to combine iterative and incremental development models by providing a cut - down version of the final product on which the client can give feedback
• The initial prototype can be improved or added extra functionality in order to produce the next prototype.

Question 80

What are the advantages of Prototyping development

Answer 80

• Allows systems to be quickly built in order to demonstrate ideas and concepts to the customer.
• Provides high degree of flexibility and developers react quickly to changing requirements

Question 81

What are the disadvantages of prototyping

Answer 81

• Make projects difficult to manage, few concrete deadlines and mission creep can st in, with developers constantly refining the product, adding less relevant functionality.

Question 82

Exam Question: Justify why the waterfall lifecycle is suited to the development of the system?

Answer 82

• – Tends to suit large scale projects … –
  
  • An OS is an example of such a big project. –
• Tends to suit projects with stable requirements … – …
  
  • And the base requirements of an OS are unlikely to change.

Question 83

Exam Question: Give 1 disadvantage of the waterfall lifecycle.

Answer 83

If a change does occur in the requirements the lifecycle cannot respond easily, often at the cost of time and money.

Question 84

Exam Question: Describe the Rapid Application Development process.

Answer 84

• – Prototype is created (1)
• – (Evaluated and) feedback used to inform next iteration (1)
• – Any changes are made (1)
• – Process repeated until…(1) …prototype becomes final product. (1)

Question 85

Exam Question: Describe two benefits of using RAD.

Answer 85

• Reduced development time (1)
  
  • due to time boxing / each subtask being given a strict time limit (1)
• Increased user involvement (1)
  
  • so issues can be identified and fixed early / more likely to meet client requirements (1)
• The requirements do not all need to be stated at the start (1)
  
  • so therefore it is more flexible (1)

Question 86

Exam Question: Compare one difference between black box testing and white box testing

Answer 86

• Black box is when the internal structure/ design is not known (to the tester)
• Black box requires limited/no programming knowledge
• White box is when the internal structure/ design is known (to the tester)
• White box requires programming knowledge