Software Evaluation Catherine McKeveney Medical Informatics 1st March 2000.
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Transcript of Software Evaluation Catherine McKeveney Medical Informatics 1st March 2000.
Software Evaluation
Catherine McKeveney
Medical Informatics
1st March 2000
Software Life Cycle
Software Engineering Software Development Software Evaluation
Software Engineering
Software engineering is the systematic approach to the development, operation, maintenance and retirement of software.
The inability of organisations to predict time, effort and cost in software development and the poor quality of the software that was produced, were only two of the driving forces behind the emergence of software engineering as a discipline.
Quality Software: Reliability
low costs
Increased Productivity
Flexibility
Functionality
Ease of Learning
Ease of Remembering
Ease of Use
Mininum Errors
Good Documentation
Readable CodeGood Design
SPONSOR USER
MAINTAINER
What is Required by Whom?
Sponser : value for £‘s User: carries out functions Maintainer: few errors
EVERYONE: RELIABILITY
Software Development Cycle
Requirements analysis and specification Design Implementation System testing Installation
Costs of Software Development
Ownership Costs 67%
Development Costs33%
Communication!
The sponsor has a general idea of what he or she wants the program to do, but may not really understand how computers work or what is involved in programming.
The programmer, on the other hand, knows a lot about computers and programming, but typically does not know very much about the task from the sponsors point of view.
Requirements Analysis
A contract between sponsor and developers Addresses the following questions:
– Who– What– When– Where– Why
Requirements Decisions Functional
– relate directly to the functioning or operations of the system
Non-functional– User Interface and human factors– Hardware considerations– Performance characteristics– Error handling and extreme conditions– Quality issues
User Interface Quality
Ease of learning Speed of use Frequency of user errors User satisfaction Knowledge retention
Interaction Styles
Menu Selection Form fill-in Command Language Direct Manipulation
Rules for Interface Design
Strive for consistency Enable frequent users to use shortcuts Offer informative feedback Permit easy reversal of actions
Training and Help!
Training manuals On-line Help Meaningful error messages
Evaluation Summary
Functionality Interface Ease of Use Speed Who uses it Manuals/Online help