First off the term 'Phase' is not relevant, at least not in the context of a question like this. That being said, 'phases' are internal development cycles of which the 'last phase' is, by definition, what we release to the system for downloading or for manufactuting (DVD's). What I suspect that you're asking is:
"What is the difference between a full 'Release', an MR (Maintenance Releases) and an MP (Maintenance Patches)?"
A full 'Release' is exactly as you would think that it is. A new version of NX which replaces a previous version. Once a file is saved in this new version it can NO longer be opened in a previous version of NX. And just so that we're clear, 'Releases' are developed in 'phases' and when you install that release and go to...
Help -> About NX
...you'll see something like:
NX 8.0.0.25
or NX 8.5.0.23
Note that a full 'Release' will be designated using the first TWO sets of digits either as X.0. or X.5. (the LAST digit is the last development 'phase' of this release) and even though they may share a common first digit they are still totally different FULL 'Releases' and nothing should be read into the particular scheme used (it's done for purely internal reasons). These releases are made available to all licensees of NX who have a paid-up maintenance contract.
Now MR's, or 'Maintenance Releases', consists of bug fixes and often enhancements which are again made available to all licensees of NX on maintenance.
After installing an MR, checking the 'About NX' site will show you something like:
NX 8.0.3.4
or NX 8.5.1.3
And the MR is designated by the THIRD digit (again the LAST digit is the last development 'phase' of the release).
They are not linked to any specific PR's but rather are a collection of PR's resolved since the full 'Release' was delivered. MR'a are also full tested using the same procedures and criteria as a full 'Release'. MR's are also pre-planned with an anticipated number of MR's for each full 'Release' although the actual number and time between MR's will vary from full 'Release' to full 'Release'.
Note that you do NOT need to install ALL MR's as they are released. They can be skipped but they must not be installed 'out-of-order'. For example, you can install MR1 then MR3 then MR4, but NOT M1 then MR4 then MR3. Also, files created/saved in a later MR can still be opened on a system only up to an earlier MR. In other words, files remain fully compatible between all MR's as long as the full 'Release' is the same.
Now MP's, or 'Maintenance Patches', are released to address specific PR's (one or more, but generally a small number of very high priority PR's). They are designed for a specific 'Release', either an full 'Release' or an MR, and must be installed as designated. While any customer on maintenance can download and install an MP, we only notify those customers who's PR's were addressed by the MP and we recommend that they be installed ONLY is the customer feels that the 'patch' will address known issues. The reason for this is because testing in generally limited to only those areas impacted by the changes made to address the PR(s) and nothing else (this is done to expedite the production and delivery of MP's). As you'd expect, MP's are NOT pre-planned, although it's assumed that there will probably be some with each 'Release'. Also, they are released as needed and are generally rolled-up into the next MR so that once a new MR has been installed, whatever MP's were previously installed are considered as having been made irrelevant and are not longer in effect.
Anyway, I hope this provided the information that you were looking for.
John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Industry Sector
Cypress, CA Siemens PLM: UG/NX Museum:
To an Engineer, the glass is twice as big as it needs to be.
