Data flow diagrams: These are diagrammaic representations to show communication of data around the current system. Arrows are used to show the direction of communication while boxes are used to represent inputs, outputs and processes. The aim of the DFD is to show how different processes in the computer system interact with the data.

Systems flow charts: The systems flow chart is similar to the DFD in the sense that it also shows the interaction of different elements of a computer system with data and each other. However, it also demonstrates the hardware used in the system. It also outlines the characteristics of the computer software that will need to be satisfied for the system to operate.

Documentation produced in analysis stage

During the analysis stage, a document that is produced is the Requirements Specification. Within this document, it is necessary to outline everything that the new system/solution should contain. It is essential that both the client analsyst and the user agree with the requirements spec as the user must be satisfied and the systems analyst is paid for it.

This is the stage wherein the system or software that has been made is installed onto devices and, if feedback is good, is mass produced for a large amount of devices. 

Maintenance

The maintenance occurs once the system is operational, and includes things like changes to the software to get rid of bugs or problems as well as additions to make it more suited to the user's needs if necessary. Finally, it also entails monitoring the performance of the system and making changes if they are requested.

Sources: http://eternalsunshineoftheismind.wordpress.com/2013/03/10/sdlc-phase-5-maintenance/

http://www.tutorialspoint.com/sdlc/sdlc_overview.htm

My brain

Calculations need to be made (e.g. processing power) to see what will be needed in the new system. Once these calculaions have been made you must also design the tasks that the new system will have to carry out, the order of certain tasks and how data will be used.

Sources: B & L A-Level computing

- take a long time

+ allow analyst to alter direction of questionning

Questionnaires

+ allow analysts to ask for opinion of large number of people

- very restrictive

- Can be very time consuming

- People don't behave naturally when being watched during things such as observation

+ things such as meetings allow a number of people to voice their opinions

Data and information must be collected (e.g through surveys) and interpreted in order to make the decision.

Sources http://www.wikihow.com/Do-a-Feasibility-Study

http://www.businessdictionary.com/definition/feasibility-study.html

http://en.wikipedia.org/wiki/Feasibility_study

OCR Computing book

1. Economic - Is it worth developing the new software. e.g. will it increase productivity?

1. Legal - does the program meet specific laws? e.g. will data be stored safely with encryption

1. Operational - Can all existing systems operate functionally with the new software

1. Scheduling - Can the project be done in a certain time frame.

Alternatively they could allow some people in the company to use the system as a pilot group and have them give a report on how effective they believe the new system is.

A company can also consider running a new system in parallel to an old system for a short length of time in order to ensure that the new system is running as expected whilst still having the old system to fall back on. They can then decide to remove the old system and fully implement the new system once they have decided the new system fulfills their requirements.

During the time in which the new system is being installed the users of the new system may potentially be left without a system to work with for some time. During this time the users can be introduced to the new system and can be trained in using it. This will mean that when the system is ready for use the users of the system will already be familiar with the system and can use it straight away.

http://www.teach-ict.com/as_a2_ict_new/ocr/A2_G063/331_systems_cycle/slc_stages/miniweb/pg17.htm

Sources - OCR Computing Book (page 7)

solutions to the problems. The solutions are what

the analyst has chosen and the job of the

specialist is to create it. If a job needs a team behind

it then it is also the specialists job to manage the team.

(Source: p.9)

by conductinging a "functional" test, which checks if the new solution works on

a basic level. If the client is satisified that the requirements specification has

been met, then the system's analyst is paid. Hence, this stage is important to

ensure payment for the analyst and to insure that the new solution is able

to solve the specified problem.

SOURCE: OCR Computing for A Level  pg 9

• Interviews: If there are a small number of important people to ask about the problems, then interviews may be held. Although they are a tedious process, it allows the analyst to alter the direction of the questions if something unplanned arises.
• Questionnaires: These allow the analyst to ask the opinions of a large number of people in a short amount of time.
• Meetings: These are the middle ground between Interviews and Questionnaires as it allows a number of people to voice their concerns without it being too time consuming.
• Observation: The analyst watches the present practices of similar systems, and forms opinions and learn more about that system.
• Documentation: The analyst collects the available documentation, I.E Reports and graphs, and studies them. It will show how the system collects, processes and presents data and information

Source : OCR Computing A Level texbook - Page 8.

Problem definition is finding what the issues and problems are in an existing system. This is normally based on the feedback of users who would have found the problems in the system but can also be done by a system analyst.

What happens at this stage?:

The system analyst looks at the problems which have been found by the users and looks into what has caused them in the system. This is important as the average user wouldn’t be able to deduce what has caused the problem so the analyst does it for them. This information is then passed on to the software engineers who work on the fine details and fix the problems.

Why is it important to define the problem?:

It is important that before we even started designing a system, that all who are involved are clear about the aims of the system. For a company who is trying to computerise a certain process to solve problems, it is important for the problem to be defined correctly so that costly mistakes do not occur within the process of development.

Often the client and the analyst are separated by their knowledge and literacy of computer systems, however the client knows exactly what problem they would like to solve. Thus, when the client defines what the problem is, it needs to be clear for the analyst to understand and for the analyst to be able to implement a solution for said problem.

What happens when the problem is not properly defined?:

When a problem is not properly defined the systems analyst will end up solving the wrong problem, leading to a failed project. This is because the systems analyst is not the one who knows exactly what problem to solve. If the wrong problem is solved then more time and resources need to be spent by the client on trying to remedy the issue thus leading to high costs for the client.

• B&L Notes Page 11

• http://www.teach-ict.com/as_as_computing/ocr/H047/F451/312/slc/miniweb/index.htm

Some programs may need an expert in programming in charge

or someone else who is better suited for implementing the

analyst's instructions.

The technical documentation

This is designed for a person that is computer illiterate
and is going to be responsible for maintaining and improving the system once it’s
operating. The documents will contain things such as the variable names that are
being used. It will also contain he program code which is fully annotated so the
user can understand it all. Testing procedures are also included and the
results given so that the same results can be obtained in the future

The User documentation

This gives the user basic instructions on how to use the
system. It contains instructions relating to the users’ view of the system
rather than any indications about the underlying software. Contents will include
how to wire up and look after the hardware, inputs and output formats, general maintenance
tasks and where to get help if necessary. The documentation will be written in
a language appropriate for the ability and not in computer jargon.

Sources: OCR computing book pg 10