Systems Development Systems Development LifecycleLifecycle

AnalysisAnalysis

Learning ObjectivesLearning Objectives

List the nine stages of the system life cycle

Explain the system life cycle as an iterative process

Discuss the information a system needs and how to collect it.

Describe what is meant by identifying the problem.

System Development Life Cycle System Development Life Cycle (SDLC)(SDLC)

At some stage, most businesses will need a new At some stage, most businesses will need a new computerised systemcomputerised system to help them with their to help them with their day to day tasks. day to day tasks. This could be a system to keep track of all the This could be a system to keep track of all the

students' names, addresses, telephone numbers and students' names, addresses, telephone numbers and grades, or it could be a new system for an online bank grades, or it could be a new system for an online bank to let customers open a high interest savings account.to let customers open a high interest savings account.

No matter what the system might be, the No matter what the system might be, the organisation should use a organisation should use a System System Development Life CycleDevelopment Life Cycle..

Identification

Feasibility study

Information Collection

Analysis

DesignDevelopment and Testing

Implementation

Maintenance

Obsolescence

TerminationTermination

Each stage of the SDLC can be terminated at any point if appropriate.

Why a new system?Why a new system?

An end user or users (person, company or An end user or users (person, company or organisation) decides that a task would benefit organisation) decides that a task would benefit from computerisation because it either:from computerisation because it either: Cannot be solved by previously used methods. Cannot be solved by previously used methods.

Or Or Similar problems seem to have been solved by Similar problems seem to have been solved by

computerisation elsewhere. computerisation elsewhere.

The manager or end user is the business or The manager or end user is the business or problem expert and knows what the problems problem expert and knows what the problems are. are.

Systems AnalystSystems Analyst

A specialist who understands computers A specialist who understands computers and computerised solutions to problems.and computerised solutions to problems. Needed because even though the client Needed because even though the client

hopefully understands the problem, they will hopefully understands the problem, they will probably not understand the consequences of probably not understand the consequences of using computers to try to solve the problem, using computers to try to solve the problem, or, indeed, whether such a solution is even or, indeed, whether such a solution is even possible.possible.

Analysis PhaseAnalysis PhaseThe systems analyst must fully

understand the nature of the problem and the business of the client.

Methods Of Information CollectionMethods Of Information Collection1.1. InterviewInterview

Advantages:Advantages:Interviewee can talk at length and so Interviewee can talk at length and so detail can be explored. Also, detail can be explored. Also, unlike a questionnaire, the direction of enquiries can be altered.unlike a questionnaire, the direction of enquiries can be altered.

Disadvantage:Disadvantage:Very time consuming and so cannot interview many people.Very time consuming and so cannot interview many people.

2.2. QuestionnaireQuestionnaireAdvantage:Advantage:

Find out the views of a large number of people very quickly.Find out the views of a large number of people very quickly.Disadvantage:Disadvantage:

Pre-determined questions and so people may find it difficult to put Pre-determined questions and so people may find it difficult to put their point of view and opinions across.their point of view and opinions across.

3.3. Group meetingGroup meetingAdvantage:Advantage:

Many people can discuss points and make their views known.Many people can discuss points and make their views known.Disadvantage:Disadvantage:

Not all the members of the group can give their opinions.Not all the members of the group can give their opinions.

Methods Of Information CollectionMethods Of Information Collection

4.4. Observation:Observation:Advantage:Advantage:

See first hand the system operating and may spot See first hand the system operating and may spot problems the actual users do not see.problems the actual users do not see.

Disadvantages:Disadvantages:

People tend not to act in the way they normally do and People tend not to act in the way they normally do and only see a snapshot.only see a snapshot.

5.5. Document collection:Document collection:Advantage:Advantage:

A clear indication of the data collection methods, input A clear indication of the data collection methods, input formats, uses and formats, uses and output formats.output formats.

Disadvantages:Disadvantages:

Volume collected.Volume collected.

Documentation often difficult for an outsider to Documentation often difficult for an outsider to understand, especially in isolation.understand, especially in isolation.

Privacy issues.Privacy issues.

After Data CollectionAfter Data Collection

All the information collected would need to All the information collected would need to be interpreted and analysed.be interpreted and analysed.

Also different solution methods would Also different solution methods would need to considered.need to considered.

Objectives & DiscussionsObjectives & Discussions

The manager’s requirements and the analyst’s The manager’s requirements and the analyst’s understanding must match, otherwise the understanding must match, otherwise the analyst will solve the wrong problem. analyst will solve the wrong problem.

Therefore, an agreed list of objectives must be Therefore, an agreed list of objectives must be created via thorough collaborative discussions.created via thorough collaborative discussions.

Problem Definition / Problem Definition / Requirements Specification / Requirements Specification /

ExpectationsExpectations

The most important part of the analysis because if The most important part of the analysis because if it is not done correctly and the manager’s it is not done correctly and the manager’s / end / end user’suser’s requirements and the analyst’s requirements and the analyst’s understanding do not match, the wrong problem understanding do not match, the wrong problem may be solved.may be solved. Discussions between all the interested parties held, Discussions between all the interested parties held,

and then a list of objectives, requirements or necessary and then a list of objectives, requirements or necessary items written up. items written up.

Therefore, an agreed list of objectives must be created Therefore, an agreed list of objectives must be created via thorough collaborative discussions.via thorough collaborative discussions.

The success or otherwise of the project depends on The success or otherwise of the project depends on the completion of these objectives, requirements or the completion of these objectives, requirements or items.items.

PlenaryPlenary

What are the stages of the system life cycle?

Identification

Feasibility study

Information Collection

Analysis

DesignDevelopment and Testing

Implementation

Maintenance

Obsolescence

PlenaryPlenary

What is meant by the system life cycle being an iterative process? When one of the stages is completed the When one of the stages is completed the

following stages may mean that the previous following stages may mean that the previous ones may need to be considered again. ones may need to be considered again.

PlenaryPlenary

What methods can be used to collect information about an information system?

Methods Of Information CollectionMethods Of Information Collection1.1. Interviews Interviews

Advantage:Advantage:Interviewee can talk at length. Interviewee can talk at length.

Disadvantage:Disadvantage:Time consuming and so cannot interview many people.Time consuming and so cannot interview many people.

2.2. QuestionnairesQuestionnairesAdvantage:Advantage:

Find out the views of a large number of people very quickly.Find out the views of a large number of people very quickly.Disadvantage:Disadvantage:

Pre-determined questions and so people may find it difficult to put Pre-determined questions and so people may find it difficult to put their point of view across.their point of view across.

3.3. Group meetingsGroup meetingsAdvantage:Advantage:

A number of people can discuss points and make their views A number of people can discuss points and make their views known.known.

Disadvantage:Disadvantage:Not all the members of the group can give their opinions.Not all the members of the group can give their opinions.

Methods Of Information CollectionMethods Of Information Collection

4.4. Observe the current system in actionObserve the current system in actionAdvantage:Advantage:

Shows present system not just views which may be Shows present system not just views which may be clouded.clouded.

Disadvantages:Disadvantages:

People tend not to act in the way they normally do.People tend not to act in the way they normally do.

Data and forms tend to be seen in isolation.Data and forms tend to be seen in isolation.

5.5. Collect printed documentationCollect printed documentationAdvantage:Advantage:

A clear indication of the data used and the collection A clear indication of the data used and the collection methods.methods.

Disadvantages:Disadvantages:Volume collected.Volume collected.

Data and forms tend to be seen in isolation.Data and forms tend to be seen in isolation.

PlenaryPlenary

What is meant by identifying the problem? Discussions between all the interested parties Discussions between all the interested parties

held, and then a list of objectives written up. held, and then a list of objectives written up. The success or otherwise of the project The success or otherwise of the project

depends on the completion of these depends on the completion of these objectives.objectives.