Open Up is a "modified" version of Rational Unified Process.[RUP][ R is for Rational].
It is customizable software developemnet process [ Infact you should always customize it to your own needs...You should have AUP where A stands for Anergy :-) ]
At RUP,OpenUP [and probably in your AUP] there are 4 phases.Each phase cosist of "n" iterations. Each iteration ends with "executable" software. But there may exception for this at "Inception".
At Inception you basically check/investigate business-technological feasibility of software...You ask yourself should we do this, and if we want to do can we able to do it? For some large projects in order to answer those questions you may have to "write some software"...But this is so rare case...
At Elaboration basically you take most risky-hard parts of the system and code it iteratively...So at the end of this phase you will had a "solid" architecture which is proven by most risky-hard part of the system features/requirements...You have "executable architecture"- not architecture stay just on "document"...
Then comes Construction in which you code relatively lower risk parts iteratively...This takes more time than the other phases generally...
Then Transition....bla bla bla....
- Each phase in RUP/OpenUP consiste of several[n] iterations...
- Each iteration generally result with executable code..
- At each iteration you basically do Requirement analysis-
Implementation- Test - and produce "small version" of system which
can be exceuted tested..
- At each iteration you incerement software...add some feature-value
RUP is iterative and incremental software developement process...
To get more undestanding i advice you to read/watch those :
- Kruchten, "What Is the Rational Unified Process?" Link
- Kruchten, "A Software Development Process for a Team of One" Link
- Larman,Kruchten,Bittner, "How to Fail with the Rational Unified Process"Link
- IJI Consulting, "Why Iterate? Understanding the Essentials of
Iterative Development" Watch at Youtube
- IJI Consulting, "Are you ready for Iterative Development" Watch at youtube