Object Oriented Software Engineering View all facts Glossary Help |
subject > measurement > recovery from failure |
recovery from failure | ||||
subject | fact |
recovery from failure | has example for a word processing program: The system will allow users to continue their work after a failure with the loss of no more than 20 words of typing or 20 formatting commands | |
is a subtopic of 4.5 - Types of Requirements | ||
is specified as the maximum-allowed impact of a failure | ||
is a kind of measurement | ||
is a kind of non-functional requirement | ||
non-functional requirement | describes a constraint that must be adhered to during development | |
must be verifiable by measuring various aspects of the system and seeing if the measurements conform with the requirement | ||
restricts the freedom of software engineers as they make design decisions because it limits what resources can be used and sets bounds on aspects of the software's quality | ||
requirement | can be gathered from various stakeholders, other software systems and any documentation that might be available | |
changes regularly | ||
has part problem statement | ||
indicates how the system is to behave | ||
is expressed as a fact | ||
is grouped with other requirements into a requirements document | ||
is normally expressed in a natural language such as English (using present tense and active voice), sometimes supplemented by a formal mathematical language, and often by some form of diagram | ||
may be given a unique number for traceability | ||
may be shown as a diagram | ||
must be agreed upon by all stakeholders | ||
should be analysed if there is any doubt whether it is realistic | ||
should be changed whenever the benefits of doing so outweigh the costs | ||
should be cut if cost-benefit analysis shows that it will have minimum benefit but still cost a lot to develop | ||
should be expressed using clear and consistent notation, using language that the customers can understand, and consistent with the other requirements | ||
should have benefits that outweigh the costs of development | ||
should help solve a customer's problem | ||
should lead to a system of sufficient quality - one that is sufficiently usable, safe, efficient, reliable and maintainable | ||
should not indicate how it will be implemented in order to give the designer as much freedom as possible to make decisions | ||
should not over-constrain the design of the system |
Next measurement: reliability Up: measurement, non-functional requirement Previous measurement: person-month