P1 - Outline the principles of systems analysis


P2 - Illustrate the stages of a development lifecycle

P3 - Explain the benefits of structured analysis

M1 - Discuss the most appropriate uses of different development lifecycle models

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Lifecycle

Here are the stages of a a system lifecycle.

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The first stage of this diagram is Feasibility which is checking if it is doable. Other diagrams may have initiation as the first stage which is briefly thinking why you need a new system and a brief plan on what order you will do things in. Feasibility is seeing if you have got the money and time for a new system and thinking whether it will be sustainable and cost effective. It is also seeing if it do able legally, technically and operationally.

The second stage is the Investigation & Analysis; this is looking into it deeper and analysing whether or not you need the new system. This can be done by investigating how your business is operating at the moment and looking how it could be improved (benefits of a new system), what services are being offered, what faults could there be in the system. Questions could be answered by talking to a systems analyst; this can be expensive but could save you money if you were to investigate.

Once you have decided to get a new system you will need a System Design; this is deciding specifically what you need, want and what you don’t. It will be where you pick features you want in the system and what interface you like best.

The next stage is System Development; this is when the system is actually built by programmers and designers.

Once the system has been built it needs to be implemented into the business, this is putting it in place and getting it working for the business. This would include setting up servers and making sure the system is working on all the PC’s and other devices and transferring data from old systems into the new one.

The final stage is Maintenance & Review. This is reviewing it to make sure the system meets its specification and the criteria’s that had to be met. During this process it will also be tested to make sure it works properly. Changes will then be made to make sure it works properly and any problems get fixed. After this maintenance will be on going as bugs and faults are found, the lifecycle will then continue.

Methodologies

There are many different methodologies which can be used to resolve information technology problems and improve systems. Methodologies are important to follow in the software development process as they can help avoid errors which could otherwise cost hundreds of thousands.

Waterfall

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The waterfall model is a simple model to follow as it only loops once and the stages are followed from top to bottom. The waterfall model is most suited to short projects and projects where the requirements are well documented and precise; this is because the waterfall model can’t adjust during projects if someone changes their mind. A benefit of having a clear goal and requirements is that targets can be set and so can deadlines to complete each stage.

Iterative

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The iterative model is good for developing when you don’t have a full specification and are not sure what you want exactly. The cycle repeats many times until the software is as desired. An advantage of the iterative model is that a lot of feedback is given which will lead to a better product. Disadvantages are that it can be costly repeating yourself over and over again as the full requirements aren’t set at the start.

Spiral

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The spiral model is good to follow for long term projects where the users are unsure of their needs and unsure whether they will benefit from a system. It is good for this as there is a lot of risk analysis which will determine whether or not it will be worth upgrading the system. This model starts in the centre and spirals its way out with stages in each quarter.

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Why business get new systems

Key drivers will change between businesses but some will change because the current one they are using appears outdated. It may be running very slowly and time is money within a business and the system could be frustrating. In Mia’s sandwich shop business some of the reasons she went into the initiation stage of getting a new system was because the old system was inaccurate because of the handwriting on the order sheet. Upgrading to an electronic system will increase the accuracy of the information and deliveries won’t go to the wrong place and the wrong things put in sandwiches which will save money. If Mia had an electronic system then it would be easier for her to compare her business with other sandwich shops or even compare with supermarkets. A lack of communication and feedback with customers or clients could also drive someone to get a new system as it would be easier to leave feedback.

Some of the benefits a business from a new system are; improved information, strategic advantage, return on investment, reduced technology cost, better applications development, reduced travel costs, reduced workforce costs, business redesign, and adherence to government regulations. A new system can improve information as it can remove human error if machines are taking over humans previous roles, for example an EPOS system in a shop, items will be weighed and price will be calculated from that and a human won’t misread from scales. A business could gain a strategic advantage from predictive software which may come as part of the new system. A new system will most likely be more efficient due to hardware improving by becoming more powerful, smaller and efficient, this will save money on electricity costs. New IT systems can also reduce the amount of staff required and therefore save money within the business. It can also remove limitations and allow the business to increase in size and manage the business from the other side of the world. New systems can eventually lead to increased customer satisfaction as the system will work quicker and the customer will be served quicker. New systems also make it easier to manage data and create reports, this can be used to find trends within businesses and earn more money. Other services can also be used with your data for predictive modelling.

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Development Tools

Business development tools

“Computer-aided software engineering (CASE) is the domain of software tools used to design and implement applications.” Wikipedia

Case (Computer Aided Software Engineering) tools can be used throughout the software development process by a business systems analysis. The tools are inspired by those used to make hardware products. Case tools are not restricted to software development and can be applied to a range of disciplines.

Tools used in feasibility stage:

A tool which is used by a business and systems analyst in the feasibility stage is a feasibility report which takes form as a document. The report will typically contain the reasons for wanting a new system, problems with the current system and user requirements along with the scope of the new system. The report will also contain the costs and benefits of a new system and finally a conclusion with recommendations of which of the proposed systems you think they should upgrade to if any at all.

A systems analysis having a simple interview with the person who runs the business could be used to help determine if a new system is feasible. The business manager may not have any idea how long it could take to develop and implement a new system and the targets they would want may be unreasonable or impossible. An interview is a great way to find out more information as a business and systems analyst which can’t be shown in a diagram. Interview also don’t require anything other than people and some notes, this is good for the feasibility stage as it doesn’t require the business owner to pay for diagrams to be created or for software.

Tools used in analysis stage:

Diagrams are often used in the analysis stage for planning and as a general structure to follow throughout the whole development. Data Flow Diagrams can be used to analyse how information will flow once the design has been created. This can then be used to find weaknesses within the system and fix them.

Here you can see a simple data flow diagram; it will be used to create relationship rules when building the system. It can be used to analyse everywhere the data will go so only the people and places that need the information will get it.

There are also Entity Relationship Diagrams which shows how entities communicate with each other. This can be useful in analysing how the system will work as you can put in limitations and an order. For example if the system managed details of students then it could limit one student to having one house address. Entity relationship diagrams can be used to organise and plan databases which will save space as entity’s aren’t being repeated in tables.

Entity Relationship Diagram

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Tools used in design phase:

Microsoft Visio is a program which can be used to create diagrams, it is designed with features which make it easy to create relationship links between tables and fields within them. Visio is a computer-aided software engineering tool.

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Software is used in the design phase to create basic prototypes or previews showing what the system could potentially be like. Software would also be used with a programmer to actually code the software for the system.

Strategies and tasks can be used while designed to make sure the new system will be as effective as it can be. Tasks can be set to different groups for developing to speed the whole process up and possibly save money.

A word processing tool could also be used in the design stage. An example is Microsoft Office Word, this could be used to type up a requirements specification and would publish the documents. These documents would then be given to anyone involved with creating the new system as the documents would outline exactly what the system will do and what will make it (hardware, software etcetera).

Workflow diagrams can be used both in the design and analysis stage. Workflow diagrams show the human workflow in a system and their interactions with people and technology. They can sometimes be used in the analytic stage to find weaknesses and inefficiencies in the current system, a new one can then be created in the design phase. The new workflow diagram should have less work than the old one as a new system should save people time/work.