Methods of Conversion

Direct conversion:

• one is turned off and the other is turned on
• requries to be confident that the new system will work as you cant go back to the older system - no fall back option
• being aware of the limitations and the functions of the system
• participants must be full trained in the operation of the new system before the conversion takes place.

Parallel Conversion:

• operating both the old and new system together for a period of time.
• allows any major problems with the new system to be ecountered and corrected without the loss of data.
• users of the sytem have time to familiarise with the new system.
• old system remains as a backup for the new system
• more work load for handling both the system
• once the new system is fully functinal and tested the old system can be ceased.

Phased Conversion:

• gradual introduction of the new system while the old system is progressively discarded.
• often used becauser the system as a whole is still under-development
• when agile methods are used phased conversion is appropriate.
• sub-systems are released
• for large organisations the conversion process makes things more manageable
• parts of the system are introduced systematically across the organisation, each part replacing a component of the old system.

Pilot Conversion:

• new system is installed for a small number of users
• users learn, use and evaluate the new system
• once the system performance is deemed satisfactory then it will be installed to use by all.
• usefull for a large number of systems
• allows a base of users to get use to and learn the system
• users can assist in training others for the final implementation of the system
• can be used as the final acceptance testing of the product
• developers and customers ensure that the system meets requirements in an operational environment,
• compatibiliy issues

Information Technology

Laptop/Computer hardware:
4gb RAM
Quad and Dual core
3GHz - CPU speed
Hard disk space(drive) 300-500Gb
Screen size and resultion: - 15inch (standard size) - laptop
Desktop - 19 - 24inch
miniturising - compact form factor usually makes an item more expensive - less quality
desktop - generic box with many components. greater selection brings the price down - no specialised components therefore more performance for the dollar.
advantage of desktop over laptop:
- can easily be upgraded
-laptop: RAM and hardrive can only be upgraded
-Desktop: anything can be upgraded

RAID

• Redundant Array of Independant Disks.
• Redundancy in computer system - multiple copies of the one thing... its excess data thats taking up unecessary space.
• Used as data is spread across multiple disks therefore due to failure of one, data will not be lost as it has back ups on multiple disks - redundant.
• faster to restore and retain datda
• primary levels are 0,1,5,6
• striping the data among multiple disks

Operating Systems:
Windows - 7, Vista, XP
Apple Varients - OSX, OS10
Linux -

Data Flow Diagram for GPS System

Context Diagram for GPS System (pg 83)

(a). A handheld HPS system gets location data from satelites and the final destination from the user. The system then directs the user to their destination.

(b). A booking system is being developed for an upcoming conference. The system recievees online bookings from conference delegates, sends payment details to PayPal for processing and approval, and then sends each delegate an email to confirm details of each booking has been made and payment has been completed.



Project Management Set 1C (Questions pg 63)

1. B
2. A
3. C
4. D
5. D
6. C
7. B
8. C
9. B
10. A
11. Define:
    Feasible: capable of being done with means at hand and circumstances as they are.
    Deadline: the point in time in which something must be completed
    Payback Period: period of time required to gain a return on an investment.
    NPV: measure that takes into account the degree of concessionality.
12. Outline factors affecting a solution's:
    Economic Feasibility: cost benefit analysis, development course, on going operational costs
    Technical Feasibiliy: ability to operate and handle various types of technology
    Operational Feasibility: support received from the new system management and existing employees
    Schedule Feasibility: consequences of not meething deadlines.
13. Characteristics of development methods:
    Traditional: involves very step-by-step stage. (UPDIT)
    Outsourcing: involves using another company to develop parts of the system or even the complete system.
    Prototyping: main aim is to verify and determine the requirement for a new system. Extends the use such that they evolve to a point where teh actually become the final solution or they becomg the sufficient detailed that they can be used to present the concept for full scale development
    Customisation: existing system is customised to suit the specific needs and requirements of the new system. It may involve alterations to system settings within the hardware and software or it may involve underlying customisation of teh actual hardware or software itself.
    Partcipant development: simply means that the same people who will use and operate the final system develop the system. As the users and participants are the people who largely determine the requirements there is little need to consult widely.
    Agile method: emphasis on team developing the system rather than following predefined structured developement processes.
14. Contrast of traditional system development with:
    Prototyping:
    Agile methods:
15. During the planning stage the feasibility study is completed, then the most appropriate solution selected, followed by determining a suitable development approach and finallu planning how the project will be managed and updating the requriements report. Discuss reasons why these activities are performed in this particular sequence.

System Development Approach

Tradition Waterfall Model: (UPDIT)

1.       Identify key characteristics of each developmental approach

      Its a sequential designing process, progress is seen to be flowing downwards through the stages of Conception, Initiation, Analysis, Design, Construction, Testing and Maintenance of the system.

2.       What criticisms are aimed at each method?

3.       What are the benefits of each method?

4.       In the article on Agile methods it speaks of “adaptive” and “predictive” methods of system development. What do these terms mean and which relate to Agile and Waterfall (traditional)

5.       Give an example of an information system that each approach is suited to.

Feasibility Studies

Feasibility studies generalll examine each possible solution option in terms of the following four feasibility criteria:

• technical feasibility
• economic feasibility
• schedule feasibility
• operational feasibility

Technical Feasibility

• concerned with the availbility of the required information technology, its ability to operate with other technology and the technical expertise of participants and users to effectively use the new technology.
• few people will be trained in the use of the application. this means it will be difficult to replace trained personnel during teh system's future operations.

Questions used to determine a solution include:

• Do we currently possess the necessary technology?
• Is the technology readily available?
• How widely used is this technology?
• Are existing users of the technology happy with its quality and performance?
• Will the technology continue to be upgraded and supported in the future?

Will the new technology operate with other existing and possible future new or emerging technologies?

Economic Feasibility

• the economic feasibility of eachs olution is determined by performing a "cost-benefit anlysis".
• this involves calculation all the costs involved in the development and implementation of each solution option.
• there are various factors that contribute to the economic feasibility of a solution and should be considered as part of a cost-benefit analysis.

           - Development costs:

• cost f development team
• system analyst and other consultancy fees
• software costs to purchase or build the software.
• hardware costs to purchase, lease and/or assemble the hardware.
• Infrastructure costs such as new buildings, communication links and power.
• installation of the syste,
• training particpation and users
• converting from the old system to the system.

           - Ongoing Operational Costs

• hardware maintenance and repair costs
• software licences and upgrade
• maintenance of teh infrastructure that supports the system
• salary/ wages for participants
• support costs for users, including ongoing training
• consumables such as toner catridges and paper.

           - Tangible Benefits

• increased sales
• cost reductions
• increased efficiency
• increased profit on sales
• more effective use of staff time

           - Intangible Benefits

• increased flexibility of the system
• higher quality products or services
• improved customer satisfaction
• better staff morale

Issues to consider during a cost-benefit analysis:

• Compares all costs with all the benefits in an attempt to determine the total return on the money invested into the new system
• Aims to determine the real benefits of each solution option. Techniques used are similar to those used by economists to analyse investment
• Issues to consider in this process include:
• Money spent on the new system could have been invested elsewhere; hence the benefits of the new system must also exceed the benefits that would have been realised without the new system. Net Present Value (NPV) requires to be determines, a positive NPV indicates a good investment and the largest NPV indicates the best investment. Negative NPV values indicate investments that should not be developed further.
• Comparing the percentage profitability of each solution option rather than just the absolute profit. This is known as return on investment (ROI) analysis. ROI describes the percentage increase of an investment over time.
• Break-even point – refers to the point in time where the new system has been paid for and it begins to make a profit. The period of time prior to the break even point is called the payback period.
• Solutions with a high NPV, high ROI and shot payback period will be the most economically feasibly.
• All these measure are based on future predictions, therefore they can not be determined with complete accuracy.
• As each client will have different needs this will affect the relative importance of each measure when determining the economic feasibility of solutions to particular problems.

Schedule Feasibility

• Largely about whether the solution can be completed on time
• The project plan and in particular the Gantt chart will specify the deadlines for the completion of each development task.
• It aims go determine if such deadlines can be met
• It should also examine the consequences should some tasks and even the entire project fail to meet its specified deadlines.
  
  Questions used to determine a solution include:
• How long will it take to obtain the required information technology?
• If new personnel need to be employed then how long will that take/
• How long will it take to retrain existing team members?
• Will retraining affect the ability of staff to complete existing tasks on time?
• Are the deadlines mandatory or are the desirable?
• If the project runs over time what are the consequences?
• Is it possible to install an incomplete solution should deadlines not be met?
• How can development of the solution be monitored to verify deadlines are indeed being met?

Operational Feasibility:

• Aims to evaluate whether each solution option will work in practice rather than whether it can just work.
• Considers support for the new system from management and existing employees.
• Solution option is likely to be operationally feasible if it meets the needs of the participants and users of the system.
  
  Questions used to determine a solution include:
• Do existing staff support the solutions option?
• Do management support the solution option?
• Does the nature of the solution “fit in” or conflict with the nature of the other systems that will remain in place?
• Will the nature of work change for participant?
• Are participants open to change or resistant to change?
• How do the end-users feel about the delivery information from the new system?
• Do participants already possess the technical skills to use the technology?
• Is the training and support available and will it remain available?

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