@Harold - yes, that's it. Michael Schluter. The book by Schluter & Lee that outlines the model is The R Factor (1993). I've been working more & more closely with Michael the last couple of years . In fact through Michael the nascent non-profit I'm part of is now associated with others from the UK, Australia, Sth Africa, Malaysia, Singapore & Hong Kong, to promote relational thinking. Through the South Africa group he's piloting a Relational Health Audit with 5 top listed companies on the South Africa Stock Exchange. They have a legal obligation this year to report on stakeholder relationships and they're using an assessment built off the Relational Proximity model.

@Jon - thanks for that link, very interesting, and yes I think she's hitting on the same point. I'll be very keen to compare her "Virtual Distance Index" with the Relational Proximity model. I reflected on some research into effective virtual teams here http://bit.ly/gIoQSU - part of a 30-day blog series I did last year examining various aspects of life through the Relational Proximity lens.