Wednesday, March 26, 2008

Shared Parameter File - A Little Clarification

Over the last few years I've posted several times about shared parameters (SP) so I thought I'd add this bit too. The context of this concerns the protection and/or management of the office SP file.

The SP file does NOT have an active relationship with your families or projects so there is no risk to your existing families or project(s) if someone gets cranky with your SP file and deletes it. Obviously making new stuff will be a bit harder but it is possible to recover them from existing family and project files. I've provided several links later in this post to other SP posts.

The SP file is used by Revit like a "dictionary", a place to store definitions/meaning. Revit uses it to define a parameter when it is applied to a Family and/or Project. Thereafter when Revit encounters it in the project it knows what it means. Thus NO active connection to the parameter in the file or the file itself.

What IS important is that your users are not creating shared parameters for the same things without communicating with each other. Why? Here is an example:

I create a parameter called "undercut" and you create one called "UNDERCUT" and someone else creates yet another called "Undercut". If we each create these in our own SP file and apply them to tags, projects and schedules we are fine as long as nobody else tries to use the content we made that use them.

As soon as we attempt to share things we will find that your undercut is different from ours because each shared parameter gets a unique GUID (global unique ID) number applied by Revit. So the name isn't the really important part to Revit. The name is important to us because it is what we see and besides we don't read numbers like those very well.

A little trivia, for most people more than four digits or things are difficult if not impossible to count without deliberately doing so. Four **** are easy to "count" at a glance but ***** is a bit harder at a glance. I picked that up from a book called Perfect Figures.

Here's what a typical Shared Parameter file looks like(with 3 parameters):

# This is a Revit shared parameter file.
# Do not edit manually.
*GROUP ID NAME
GROUP 1 Steel
GROUP 2 Exported Parameters
GROUP 3 Projects
*PARAM GUID NAME DATATYPE DATACATEGORY GROUP VISIBLE
PARAM 29321d2c-b02c-49c1-ab8b-c41c18fcac00 Building Letter TEXT 3 1
PARAM c17fad8a-7479-4572-9f62-8da94b702446 Weight NUMBER 1 1
PARAM 0d7b92f5-b62e-49f5-9167-263cebac962b OLF NUMBER 2 1


The portion in red is the GUID.

The best strategy is to make everyone well aware that Shared Parameters are to be managed and by whom. If they are created from a copy of the office SP file it is possible to export the parameter to the original so it isn't completely unacceptable to let people make them on their own. It IS unacceptable to do so without properly communicating it to the person in charge of them and their team(s).

That said, placing the office standard as a read only file will allow people to use them without being able to add them. They will need to get them added by the responsible party and that person better be ready to "jump" because this stuff always gets figured out at the last minute.

Finally, if someone loses the SP file it is possible to export shared parameters from projects that have them into a another or new SP file.

Here's links to the previous Shared Parameter posts:
What are Parameters and Why Should I Care?
Sharing Parameters Overview (Part 1)
Walking on Thin Ice
Making a Shared Parameter File (Part 2)
Shared Parameters Part 3
Shared Parameters Part 4
Ignore Good Advice
Home for Unwanted Doors

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