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Grades

“straight forward assignment”
it’s all about writing the tests
use java 17
write 1 or more tests for every method (including constructors)
CREATE YOUR OWN EXCEPTIONS (not stated in assignment, but he said he wants it)
test custom exceptions
- just do a try catch (try method, assert true if correct exception is caught, fail if wrong exception is thrown)
V → $(x, y, z, α, β, ...)$
Vector(3,0); -> V = (0,0,0)
module settings → global libraries → from maven → org.junit.jupiter:junit-jupiter-api:5.10.0

software change is inevitable
- new requirements emerge when the software is used
- business environment changes
- errors must be repaired
- new computers and equipment is added to the system
- performance or reliability of the system may have to be improved
a key problem for all organizations is implementing and managing change to their existing software system
components are added or updated with each release → most releases are a condensed version of a development cycle
development team & maintenance team may be different
COBOL does not translate to 4th generation languages (COBOL is procedural, 4th generation are all object-oriented)

Evolution: effectively deals with software that has already been written & in service life
- should the software be maintained or retired?
  - 60-90% of the cost of software is maintenance → due to large investment in development & business importance
  - business models change
  - large budgets to keeping software relevant in the business
  - typically maintenance is a continuous “development cycle”
Servicing: the software remains useful but only changes made are those that are required to keep it operational (bug fixes) → no new functionality is added
Phase-out: software may still be used but not further changes are made to it
Urgent change requests: changes that may have to be implemented without going through all the stages of the software engineering process
- serious system faults, change to the system environment, business changes (e.g. release of a competing product)

System hardware: legacy systems may have been written for hardware that is no longer available
Support software: legacy system may rely on a range of support software, which may be obsolete or unsupported
Application software: application system that provides the business services is usually made up of a number of application systems
Application data: data that is processed by an application system → may be inconsistent, duplicated, or held in different databases

Note

Ended slide 22 (but skipped half of them)