This from the visio help using "org chart import"
Create a text data file to generate an organization chart
1.. On the File menu, point to New, point to Organization Chart, and then
click Organization Chart Wizard.
2.. On the first wizard page, click Information I enter using the wizard,
and then click Next.
3.. On the next wizard page, click Delimited text, and then type the name
of the file. Click Browse to locate the folder to which you want to save the
file, click Save, and then click Next.
4.. When you click OK, a text file opens with sample text in place. Type
over the sample text to create your data file. In the text file, on the File
menu, click Save, and then close the text file.
5.. Follow the remaining wizard pages to create an organization chart from
your new text data file.
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