| Article ID: | iaor20102843 |
| Volume: | 36 |
| Issue: | 4 |
| Start Page Number: | 484 |
| End Page Number: | 491 |
| Publication Date: | Jul 2008 |
| Journal: | Operations Research Letters |
| Authors: | Adelman Daniel |
We use Palm calculus to derive a simple, intuitive system of two linear-quadratic equations and two unknowns, whose algebraic solution yields Harel's (1988) upper bound to the Erlang loss probability. We then derive a sequence of progressively stronger systems of equations, which eventually become exact. We provide two example applications.