Why do we drive on Parkways and park on Driveways?

It never ceases to amaze how the name of an item will influence a person to believe that item may actually carry that property.  High Definition Hair Color Products probably doesn’t mean the same thing as High Definition Television Sets when considering what ‘High Definition’ is representing.  Just because an object carries a certain name does not guarantee that it will have that characteristic.  The Name should provide clarity, not add confusion.

A parameter named Voltage means nothing to describe what information it actually contains.  A user wants to believe that that parameter is an actual value of Voltage, but it could easily be a just number or simply text.  Also, lists are shown in alphanumeric order.  Looking for Air Flow parameters based on a system name would require searching through an entire list, even in the same group, if they are not somehow bundled together.  Using a Prefix of 227 will bundle all the Air Flow parameters together in one area.

All the possible attributes for a shared parameter, the Disciplines, Types and Groups of Parameters, were considered when developing a Prefix Standard in the Labeling Convention.  The categories naturally developed based on the available options.  The order of the numbering also aligns with the current list of options when working with Shared Parameters.

Some standard libraries have developed a brand for each parameter, in order to identify that parameter with the library it belongs to.  This requires every equation or reference to a parameter to show that brand in it.  Most libraries do not use any special naming procedure that easily lends to confusion once multiple parameters are found in the same model, carrying the same name, but different GUIDs.  Selecting the correct parameters becomes very difficult.  The Prefix provides a recognizable brand that is more about function than just recognition.  As parameters are sampled, they are renamed according to the Labeling Convention and obviously there are many instances where duplicate or redundant parameters turn up.  The Master Library does not contain duplicate parameters that carry the same name, giving priority to the dominant parameter.

300Voltage is a Text Parameter and 321Voltage is an Electrical Potential Parameter.  300Voltage is omitted from the Master Library, because it is not necessary while a 321Voltage exists.  Similarly, 224PressDropCoilCooling is a Shared Parameter for the pressure drop across a cooling coil that is a unit of pressure and is found in the Revit Master Shared Parameters v2.1 from Autodesk.  Another example is 320FullLoad, which is a parameter for Full Load Amps that is based on Current also found in that library.

The Prefix helps sort the Library of parameters in an understandable order, provides a branding as well as important information on the parameter.  A quick reference of the Prefix Sheet can be seen HERE.  There is also a PDF of the Prefix Standard available when you download the Master Library packet HERE that is FREE.  When dealing with Units of Measurement, this will hopefully become clearly beneficial.  That is for another time.

-Craig

www.ModelingDynamics.net

What is a GUID anyway?

Computers don’t think like humans, yet.  There needs to be some form of code that allows for a massive database of possible parameter combinations to contain data.  The idea of one organization managing all those codes in the world just doesn't make sense.  A Global Unique Identifier, or GUID, is a 128-bit alphanumeric value that is created by a random generator ^[1].  If you are worried that the world will run out of these values, know that there are about 5.2x10^36 possible combinations.  Still concerned? If each person copied the entire internet every second, there would only be enough GUID code combinations to last about one billion years ^[2].  Even if those numbers are a little off, the concept is that there is a vast space available.

Keeping that in mind, it makes sense for Autodesk to utilize the system within the B.I.M. software of Revit.  It is critical for Revit to protect the information of a model from corruption.  Using the GUID values helps accommodate this.  With this advantage, also comes a major disadvantage.  If two shared parameters carry the same Name, yet have different GUID codes, then they will not populate the same tags or schedules.  The GUID must be exactly the same for parameters to work collaboratively.

It takes some work to get one company into a standard where everything works well internally.  However, any Revit Families developed end up being generic for those families to work from one project to the next.  Families from a Manufacturer don’t tend to work unless someone takes the time to modify the parameter assignments to fit a specific schedule or tag.  When available time becomes a factor, it is easy to drop schedules completely and revert back to drafting the information.  If only manufacturers were developing their families using the same shared parameters that companies are using in representing equipment selections in the B.I.M. models.  With the amount of possible GUID assignments, it is no coincidence that some Shared Parameters with the exact same GUID information are showing up in multiple sources.

Standard parameters are out there, are being identified and placed into the Master Library.  As the Master Library is adopted, families and schedules will begin to work together, regardless of where they come from.  Manufacturers can begin to provide equipment using the Master Library, if not already.  Companies would be able to standardize their own schedules and not have to worry about the fields populating correctly.  No more manually drafted tags and schedules and the information can be provided that is referenced throughout a model.  Swing by HERE for your own Free copy of the Master Library.

-Craig

www.ModelingDynamics.net

[1] http://en.wikipedia.org/wiki/Globally_unique_identifier

[2] http://betterexplained.com/articles/the-quick-guide-to-guids/

Not a What or a How, but a Why

It isn't What that drives you or How that intrigues you but the Why that compels you.  Technology is advancing, but the Why must remain the driving force in the scope of a project.  Dreaming big is great when time and budget are thrown out the window.  Showing What is possible means nothing when it cannot be accomplished in a necessary amount of time.  Even showing How it can be done, may not convince anyone if they don’t see an advantage to the effort.

It is the Why that has to compel us to achieve the What through the How.  Why draw on paper when the information can be developed faster on a computer?  Why draw multiple 2D views when a single 3D view can create the same content?  Why design and then model the content separately when the design can aid in the modeling?  Why manually change sizing when the design changes in the model can automatically provide the correct size as controlled inputs change?  Why manually draft schedules when the schedules populate as model elements are placed?  Why even settle for one manufacturer’s schedule when more standardized schedules are needed from project to project?  So, the question becomes Who is going to provide this, What does it look like, How is it accomplished and When will it be available?  

What if the shared parameters were already out there?  How could they be identified?  How is it possible to know which ones to use?  In a constantly growing library of shared parameters, a collection of parameters began to rise to the top.  These top parameters were found in multiple families across many major manufacturers and companies.  The Master Library is based on the discovery of these parameters and follows a Labeling Convention that identifies the purpose of each parameter.  

Hopefully, the Why becomes evident and the What and How will follow.

- Craig

www.modelingdynamics.net