Week 4 - Accounting Information Systens Development Flashcards
What are the 5 stages in the Systems Development lifecycle?
- Systems Analysis
- Conceptual Design
- Physical Design
- Implementation and Conversion
- Operations and Maintenance
What is one of the main things included in Phase 1: Systems Analysis?
A feasibility study
What is the purpose of a Feasibility study?
To determine whether the system we are looking at will be fit for our purpose
What 5 things are considered in a feasibility study?
- Economic - Do the benefits outweigh the costs?
- Technical - Can we use the existing hardware with the new system?
- Legal - Does the system comply?
- Scheduling - Can the system be developed in the allocated time?
- Operational - Do we have the people to develop the system?
What is the second stage of the systems development lifecycle and what does it involve?
The second stage is: Conceptual Systems Design
The developer of the system evaluates what is the best way to design the system. What fields do we need? What layout suits our needs?
What is the third stage in the systems development lifecycle? And what elements are considered in this stage?
The third stage is: Physical Systems Design.
This stage is concerned with actually building the new system.
Output design
File and Database design
Input Design
Program design
Control design
Are all considered in this stage of the systems development lifecycle.
What is the fourth stage of the systems development lifecycle?
The fourth stage is the Implementation and conversion stage.
What needs to be considered in the fourth stage of the systems development lifecycle?
Implementation plan - Develop a timetable of all activities.
Select and train staff
Test the system
Plan system conversion
What are the three ways to test a system?
- Walk through
- Processing test data
- Acceptance test
How is a ‘Walk Through’ test completed?
One transaction is took through the system step-by-step to asses whether the system is working correctly.
How is a ‘Processing Data Test’ conducted?
Multiple valid samples of test data are sent through the new system and the results compared with what should have been outputted.
How is an ‘acceptance test’ conducted?
Real sets of old data (last months) are put through the new system and compared to the results from the old system.
This has the benefit that the data used is from the actual company and is therefore more useful in assessing how well the new system performs.
What are the four ways in which we can carry out systems conversion?
- Direct Conversion
- Parallel Conversion
- Phase-in Conversion
- Pilot Conversion
Describe Direct conversion
The old system is terminated and the new system begins immediately.
Describe Parallel Conversion
Operate the old and new system simultaneously for a period of time.
When we are confident the new system is working correctly, the old system is turned off.
Describe Phase-in Conversion
Elements of the old system are replaced with elements of the new system, over time the entire old system is replaced.
Describe Pilot Conversion
The new system is implemented in only one department to start, if it works well it is rolled out throughout the organisation
What is phase 5 of the systems development lifecycle? And what sort of considerations are made in this phase?
Phase 5: Operations and Maintenance.
Once a new system has been implemented, it is important to review it.
- Does the system meet the organisations goals?
- Are users satisfied?
- Is the system reliable?
- Is the systems accurate?
- Is the system sufficiently safeguarded from error?
- Is everyone trained to use the new system?
List the 7 reasons for behavioural problems occurring I systems development.
- Fear - Fear of failure/unknown/losing status/pressure
- Lack of top management support
- Bad prior experiences - Previous system experience wasn’t good?
- Poor communication - Employees don’t understand why change is needed?
- Disruption - Effects the internal ecosystem and throws things off.
- Biases and emotions
- Personal Characteristics - Age/Openness to new tech?
Give 4 ways to mitigate behavioural problems.
- Management support
- Satisfy users needs
- Involve users in development
- Provide sufficient training
- Performance evaluate
- Test prior to new system implementation
- Keep the system simple
What are the three ways in which a new AIS can be obtained?
- Purchase
- Develop in-house
- Outsource to outside organisation
What is the process for purchasing a new system?
- Select a vendor
- Request for proposal (RFP) that meets needs.
- Evaluate proposal
- Make selection based upon criteria
Name some advantages and disadvantages of developing a new IAS in-house
Advantages:
- Tailer to meet needs of company
- In-built flexibility for growth
- ‘Local Expertise’ - Issues can be solved sooner.
Disadvantages:
- Requires significant time, energy and money.
- Complexity of the system may be limited when developed in house.
- Lack of Qualified staff
- Poor top management support
Name some advantages and disadvantages of outsourcing to outside organisation
Advantages:
- Allows companies to concentrate on their core business activities.
- Access greater experience and expertise.
- Takes less time to develop and implement.
- Facilitate downsizing (make people redundant)
Disadvantages:
- Inflexibility
- Loss of control
- Poor service
- Lack of ‘local knowledge’.
- Increase risk
