System analysis Flashcards
What is a pilot changeover?
- In pilot only a small number of business sites run new system while rest use the old system
- This way, if the new system is faulty or there are problems only a few sites are affected
- ideal for businesses with many similar branches
- Not suitable for company speed out across many branches doing something different or companies with only a small number of sites
- Suitable for different offices
What is phased changeover?
- Part-by-part implementation(part of new system used while old system stays)
- If there are problems remainder of new system can be delayed and old system is used until it is solved
- A phased approach can only work if systems are compatible (old and new)
- Works best for small company upgrading an existing system or implementing a brand new system
- Not suitable for companies with many different premises
- Suitable for different departments
What is parallel changeover?
- Old and new systems run at the same time
- Used if cannot afford for the system to fail at any time
- If new system fails old one is there as a backup
- Could cause confusion for staff and customers having 2 systems
- Expensive as have to pay temp staff or overtime for current staff to operate both systems
- Can be very tiresome and inefficient using 2 systems so not desirable to do for long
- New system can be available immediately if needed
What is direct changeover?
“Big Bang” changeover
- Old and new systems swapped
- can be very dangerous and costly as if new system fails there is no backup and could be a complete shut down
- Should only be done when old system is unusable or there is no old system
- Can be used when failure wouldn’t be catastrophic
- If implemented well can be the least disruptive
- Will take time for staff to get used to new system
- New system available immediately if needed
What is implementation?
- The process of installing new system at client site and putting it into use
- Occurs after software + documentation have been produced
What is agile methodology?
- Flexible alternative to waterfall methodology
- Value collaboration and people over processes and tools
- Spend much more time meeting regularly with clients to discuss system development
- Favours using time to develop software rather than detailed documentation
- has various implementations including extreme programming and scrum
- Focus on communication, feedback and simplicity make it possible to develop very well written programs quickly
- Some agile techniques such as pair programming are not popular among developers or managers and a lack of documentation and specific deadlines can lead to problems with customers unfamiliar with the approach
What is documentation?
- Focus on this phase is documentation that will go to the end user and customer- the documentation for the development company is produced throughout life of project
- This phase needs to happen in parallel with software development so they are completed at the same time.
- Documentation needs to be planned, designed and tested - written by technical authors alongside developers
What is waterfall methodology?
-Initially designed for use in manufacturing + engineering environments where products were based on hardware rather than software
-Different stages are arranged in order with each stage feeding into the next
-No stage of development can begin until preceding one has been completed
-Each stage ends with a deliverable or handover document produced to inform next stage :
= Deliverables are detailed and accurate
= Advantage as they are used to produce concrete deadlines
- Simple to understand +suitable for large programs where requirements are clearly understood
-It is very bad at reacting to changing requirements and is not suitable for projects where the requirements may not be fully understood
What does technical/maintenance document contain?
#Algorithm designs - Normally presented in pseudocode or flowchart #Any form of diagrams used in analysis and design #The data structure - What data structures have been used, database/table designs and any other information about where data needs to be stored #Annotated code listings - Code listings that abide by coding standards set out by development company. Normally self-documenting and/or annotated. #Data dictionary - Describes all fields that need to restored in data structure e.g data type/size etc. #Design documents- Any relevant documentation from design phase #Hardware and software requirements #Configuration guide and options - how system can be configured #Variable lists - Lists of key variables including data type and purpose
What is technical/maintenance documentation?
- If new system is bespoke, there needs to be at least one person able to ensure it runs smoothly once implemented
- They ensure system is set up and configured correctly + it has smooth day-to-day running
- To help technicians use system , technical documentation produced by developer
- Need to know how database was setup, how system is configured and what hardware is required to install system - also need access to design document and code for deeper understanding
- can use technical language as technicians will understand
What does user documentation contain?
- Step-by-step getting started guide for main features of system
- Installation guide
- User guide focusing on user tasks
- Reference manual
- Online help, at both individual controls and task level
- Error messages and trouble shooting guide
- Frequently asked questions(FAQs) detailing common problems and questions
- Glossary
Advantages and disadvantages of phased/pilot changeover
-exam q
Advantages:
- Difficulties identified in one area can be resolved and managed in next
- All staff can focus on one area to resolve any problems
- Problems can be fixed quicker as more experts to resolve problems
Disadvantages:
- Might cause problems in changeover period when need to communicate with each other and have different systems
- Slower to get new system up and running compared to other methods
What is user documentation?
- User will, in most cases require training in order to use system
- There may be a training course with accompanying manual. There will also be a full set of documentation for user after training
- User documentation should be targeted towards user and their needs (Straightforward and avoiding technical terminology)
What are the feasibility studies?
Economic feasibility Time feasibility Technical feasibility Political feasibility Legal feasibility
What is economic feasibility?
A project has specificities budget that takes into account:
- software licences
- Hardware
- human resources (wages)
- Development company’s running cost
- Profit is also taken into account
Human costs are most variable + account for majority of budget - e.g delayed project, someone getting a pay raise or need for more expensive contractor
also important to build in some flexibility
-If company doesn’t make profit won’t take on project
