> There is nothing about contracts which require that you can only have one active at the same time, or that that current one must be open ended. Agreed and y

> There is nothing about contracts which require that you can only have one active at the same time, or that that current one must be open ended. Agreed and yet for many systems, that flexability still eludes. One example I personally experienced was changing a phone contract. The contract had run for many years, so could be cancelled any time with one months notice. The new plan and contract was much better and yet a limitation played out doing this. Ended up that the systems at the telco was unable to activate the new contract until the old contract had ended. Whilst a new contract could be physically signed in a shop with a start date of the day of signing, and logged into the system. The provisioning backed was unable to activate it until the old contract had ceased as you can't have two contracts for the same phone number. That I do believe is a case of - whilst some things can run in parallel, others are locked to a single dependant resource. But every rule has an exception, it is with good design that you limit those exceptions impact.