what does defining + understanding problem involve
formally identifying precise problem to be solved, determining if existing solution is viable or new solution is needed
things to consider when defining problem
- client’s needs
- compatibility with existing software/hardware
- possible performance issues(internet/graphic intensive systems)
- boundaries of system
what is considered a need of the client
an instance in which some necessity or want exists, implies some form of solution is required to meet the need
importance of articulating needs of the client clearly
so that it will be easier to develop clear picture of problem to be solved
how can a set of functionality requirements be created
through consultation + analysis of general statements
systems analyst function
- analyses systems
- determines requirements
- designs new info systems
tools to analyze needs
surveys, interviews, time management studies, business analysis
surveys
completed by all key personnel; gathers info from lots of people, though detail + explanations are limited
interviews
allows participants to express needs; detailed + good explanations, though expensive
time management studies
how much time spent on function; highlights priority areas
business analysis
examining different aspects of a business’ activities in search of areas for improvement; cost benefit analysis = profitable return
reason for developing product
a client has need for it
requirement meaning
features, properties or behaviors systems must have to achieve its purpose
functionality requirement meaning
describes what the system will do
- if achieved, needs = met
- should be continually examined during d+d
- final evaluation: based on how well original requirements were met
how to evaluate degree of success/failure of requirements
requirements must be stated in a way which can be easily verified; using scientific/mathematical statements
compatibility issues
relating to range of OS, browsers, hardware, devices available for software, caused by various connections operating at various speeds resulting in errors/loss of connectivity
common compatibility issues
- versions of systems
- COTS products, parent updates
- graphics cards != graphic code libraries
- screen resolution + size
- labels + fonts + other UI
- server connection over wireless networks
- HTML != W3C standards
performance issues
- performance of systems are different in real-world conditions, and testing environments should simulate this
- for non-custom solutions with broad audience: specific performance requirements are hard to meet
- use efficient algorithms, visual aids
common performance issues
- computer doesn’t seem to respond after function initiated
- poor response times, usually in data entry
boundaries meaning
defines limits of the problem/system to be developed
boundary considerations
- anything outside of system = environment
- system interacts with environment via interface, input + output via interface
- keyboard = human/computer interface
- internet service provider(ISP) = computer/internet interface
why are boundaries needed
to determine boundaries of the problem; what is and what isn’t part of the system
- items in environment need to be considered if they will affect system
- interface needed if items within environment need to influence system
system interaction with items in environment
items in environment can affect system, though system cannot alter environment
what to do when defining a problem
define boundaries of problem so customer has realistic expectations of the limits of the new system
