AS11 Flashcards
Feasibility
- Establishes whether or not a project can be completed given the scope laid out.
- Is it worth it?
Economic Feasibility
- Can the project pay for the hardware, liscences, human wages and running costs in the given budget?
- What is the profit?
Time Feasibility
- Will the project be done in time? (Risk of going over budget, making a negative impression)
Technical Feasibility
- Can the project be done with the resources available?
- Is the project doable with current accessible technology?
Political Feasibility
- Does the project go against the beliefs of certain people?
- Will the media report on it in a negative light?
Legal Feasibility
- Does the project comply with the law?
- Any chance of being sued?
Project Requirements Specification
- Produced at the end of analysis.
- Outline of how to create successful project.
- Poorly defined = delays/increased costs.
Observation
- Analysts shadow employees, see how the business works.
ADVANTAGES: - Could pick up parts of system that are not obvious to customer.
- Confirms information gathered through other methods.
DISADVANTAGES:
* - Some people may feel threatened/uncomfortable.
* No guarantee that some subtle system parts will show during observation.
Questionnaire
- A set of questions about the system, normally given to staff.
ADVANTAGES: - Can be given to big population.
- Can get a large number of responses.
DISADVANTAGES:
- Hard to design.
- Requires system knowledge.
- Not all questionnaires sent out will be completed.
Existing Documentation
- Analyst gathers documents relating to new system to infer what data will need to be stored.
ADVANTAGES: - Analyst gains understanding.
- Reliable documents.
- Document trails help support the analyst’s picture of business processes.
DISADVANTAGES:
- Documents give limited view of system.
- Documents may contain sensitive information.
Interview
- Analysts pick some key stakeholders and ask targeted questions about current system.
ADVANTAGES: - Large amounts of information can be gathered.
- Interviews produce detailed responses.
DISADVANTAGES:
- Time consuming.
- Interviewees may not be truthful. Reponses need to be verified.
Requirements
- Help keep scope of project.
- Developers can be paid based on requirements.
Types of Requirements
- Interface (Where is user interaction?)
- Functional (What will the system do?)
- Performance (e.g. response times.)
Design
- Hardware/software choices.
- Data structure design.
- Input/Output design.
- Processing design.
Flowcharts/Data Flow Diagrams
- Flowcharts represent an algorithm.
- DFDs represent how a system will process information. (Multiple levels, distinction between internal/external parts)
Direct Changeover
- Swaps over all data at once/Switches off one system entirely.
- Only used when older system unavailable.
- Cheap, no duplication.
- Risky, have to transfer all data first.
Phased Changeover
- Old system active, new one phased in chunks at a time.
- Used when a small company upgrading/implementing new system.
- Less risk of system going down, staff introduced to new system in small stages.
- Takes long time, difficult to integrate new system into old one.
Pilot Changeover
- New system tested in small numbers of areas before fully implemented.
- Used by big brands.
- Only small part of business affected, new system staff can train old system staff.
- Extra work for IT staff, communication between systems harder.
Parallel Changeover
- Both systems used, once new system is stable, the old one is discarded.
- Used when the system cannot afford to fail.
- Less risky, less stress.
- Time consuming, extra cost.
White Box Testing
- Structure is tested.
- Knowledge of code required.
- Several paths created by control statements. Each path tested.
- Carried out by developers.
Alpha Testing
- Unstable preliminary build.
- May not work.
- Carried out by developer/team.
Beta Testing
- More stable than alpha builds.
- Still contains some errors.
- Carried out by customers in live models. Report faults.
End User Testing
- Final phase.
- Uses real data.
- Tested by customers. They ensure developer has met requirements.
Adaptive maintenance
- Companies fix bugs/add functionality to system.
- Customers can implement basic models, then upgrade.
- Helps businesses get running quickly.
Corrective Maintenance
- Fixes problems as they arrive so system matches specification.
- Customers take out support contract that asks developer for this kind.
- No functionality updates.
Perfective Maintenance
- Completely matches original system.
- Improves on performance and functionality at request of users.
Black Box Testing
- No knowledge of code required.
- Tester provides input, observes output. Identifies how system responds to certain inputs.
User Documentation
- For those who don’t understand complex technological ideas but work for the client/Employees that need training.
- Allows novice users to interact with the system/Needed for training.
Technical Documentation
- For experienced users who have good understanding of technological concepts/Those who ensure system has been configured correctly and is running smoothly.
- Needed to know how database was set up/what hardware is required. Allow for greater understanding of system.
5 Features of User Documentation
- Step by step getting started guide for main features.
- Installation guide.
- User guide.
- Reference manual.
- Error/Troubleshooting guide.
5 Features of Technical Documentation
- Diagrams used in analysis/design.
- What data structure has been used.
- Hardware/Software requirements.
- Any relevant documents from design phase.
- Algorithm designs - flowcharts.
Full Backup
- Copies all files/Provides complete set of the data.
- Everything is backed up at once, files can be restored quickly.
- Most files do not change/leads to redundancy, takes longer to carry out, security concerns.
Differential Backup
- Copies only files that have been changed since last full backup.
- Faster than incremental/full, takes up less storage.
- Requires more storage space, longer time needed to restore files than with incremental.
Incremental Backup
- Copies only files that have been changed since the last backup of any type.
- Faster backup time, less storage required.
- Recovery process takes longer, problems may occur if any backups corrupted.
Disaster Recovery Plan
- An organisaton stores all of its data in a data centre, including sensitive data.
- A DRP is a document which details the steps that will be taken in the event of a man-made or natural disaster to protect/recover the data.