Zusammenfassung der Ressource
Computing - Sytem
analysis & design
- A computer system
consists of: -The hardware
- The software - The data
-The people
- When companies
needs a
computerised
solution to a problem
they call an system
analyst to over see:
- Analysis: finding
out whats
needed.
- Design: Designing the new system
- Development: Creating the new system.
- Testing: Making sure it works.
- Implementation: Getting it up & running.
- Business may need an
new computer system
because:
- They do not have one &
still relay on paper based
system.
- Competitors have
better systems.
- The one they are
using no longer
serves its purpose.
- System analysis:
Invovles a detailed study
of an existing system &
requirments of a new
system.
- System
design:
Involves the
design of a
new system.
- Feasibility study: A
preliminary
investigation carried
out by a systems
analyst to determine
if they need an new
computer system.
- It will involve:
- Requirment
analysis:
what the
new system
needs to do.
- Techincal
report:
Technology
exisit,
difficult to
build?
- Schedule
report:
Developed
in time
scale?
- Cost effective
report: New system
generate more
money than it
costs?
- Budget
report: New
system
developed
within agreed
budget.
- Methods of Investigation:
- Questionnaries: to staff & management,
simple questions, fast to collect data.
- Interviewing: more detailed questions.
- Observation of
procedures: Watching
people at thier work
place.
- Team Work
- People working
together and
co-operating.
- Effective team member you must -
- Listen
- Share
- Help
- Interact
- Data Flow
Diagrams,
Symbols used:
- External Entity - Data source or data destination e.g. Customer.
- Process - An operation performed on the data.
- Data store - Represent a file held on disc or magnetic tape.
- Data Flow - The arrow represents movement of data between entities
- Change-Over:
- Piloting:
- Direct Changeover
- Parallell Running: