1. Software Evaluation Catherine McKeveney Medical Informatics 1st March 2000

2. Software Life Cycle u Software Engineering u Software Development u Software Evaluation

3. Software Engineering u Software engineering is the systematic approach to the development, operation, maintenance and retirement of software. u 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.

4. Quality Software: Reliability low costs Increased Productivity Flexibility Functionality Ease of Learning Ease of Remembering Ease of Use Mininum Errors Good Documentation Readable Code Good Design SPONSORUSER MAINTAINER

5. What is Required by Whom? u Sponser :value for £‘s u User:carries out functions u Maintainer:few errors EVERYONE:RELIABILITY

6. Software Development Cycle u Requirements analysis and specification u Design u Implementation u System testing u Installation

7. Costs of Software Development

8. Communication! u 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. u 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.

9. Requirements Analysis u A contract between sponsor and developers u Addresses the following questions: – Who – What – When – Where – Why

10. Requirements Decisions u Functional – relate directly to the functioning or operations of the system u Non-functional – User Interface and human factors – Hardware considerations – Performance characteristics – Error handling and extreme conditions – Quality issues

11. User Interface Quality u Ease of learning u Speed of use u Frequency of user errors u User satisfaction u Knowledge retention

12. Interaction Styles u Menu Selection u Form fill-in u Command Language u Direct Manipulation

13. Rules for Interface Design u Strive for consistency u Enable frequent users to use shortcuts u Offer informative feedback u Permit easy reversal of actions

14. Training and Help! u Training manuals u On-line Help u Meaningful error messages

15. Evaluation Summary u Functionality u Interface u Ease of Use u Speed u Who uses it u Manuals/Online help