other people who know how to program it (should you retire/leave).
This is an important factor that I like to consider also. Not so much for me retiring, but more so with having confidence that a system can be maintained after I am finished the project and without a lifetime dependence on me.
I have always based decisions on my observations and listening to others opinions. Today I began thinking of how can the personnel knowledge base (in other words, what are most people familiar with) of a geographical area be roughly determined without an extensive market research project. My idea I came up with is a simple one....search resumes.
To test this, I did a quick search to compare against my experience of seeing that both AB and Siemens PLCs are significant in the Southeast, but AB is more dominant. Although this is less than an extensive scientific research project, the results match my experience. Here are the results:
50 mile radius around Atlanta, GA using search terms "Allen Bradley PLC" : 16 pages of resumes
The same search, except in "Siemens PLC" : 11 pages of resumes
On a few occasions I have made the statement that it is far easier to find developers for AdvancedHMI than any other HMI/SCADA on the market. This statement was made purely on my experience without any data to back it up, so I wanted to see if the same test would back up my statement.
I started with a couple of the most popular on the market, FactoryTalk, PanelView, and Wonderware. Here are the results:
FactoryTalk : less than 1 page of resumes (this actually surprised me, so I added PanelView)
PanelView : 2 pages of resumes
Wonderware : 3 pages
Now to compare AdvancedHMI... Since AdvancedHMI is merely an extended toolset for .NET and Visual Studio, any .NET programmer will have the pertinent knowledge to jump right in and develop with the software, so I performed a search of ".NET programmer". The search results maxed out the 20 page limit of the resume search site, which can be interpreted as there being a minimum of 7 programmers that can work with AdvancedHMI for every 1 Wonderware programmer.
These searches made me quite curious, so I tried a few more:
Beckhoff : less than 1 page
Wago : about a half page
Red Lion HMI : less than 1 page
Indusoft : less than 1 page
Citect : 1 page
WinCC : 1 page
Keep in mind this is not a scientific research by any means, but possibly a simple way to get a rough idea of what knowledge currently exists in a geographical area.