Sometimes when I look at SOA infrastructures and there are a couple of single points of failure or bottle necks. Security is normally one and often its an ESB or a registry. The point is that all requests go through these elements. Now if they are scalable this can be alright, the challenge however comes if the funding and the KPIs for these areas aren't aligned with the overall goals or even compete with the individual service goals.
What do I mean? Well last Monday I had one of those nightmare travel days going into SEATAC from LHR. First off I wasn't in business, secondly we had a delay due to issues in Iceland so it took longer... then we landed.
The US Immigration folks are a great example of the problem that comes when something, whether in government or in business, has a monopoly over a gateway or access to other services. While the service provision goal might be to get out out the airport as quickly as possible and make it as painless as possible this is nothing to do with the objectives of the immigration (and customs people). Two 747 planes landed at the same time from Europe, to handle the several hundred Europeans getting off these flights there were.... THREE people assigned by immigration to handle the volume.
Seriously THREE people for two 747s full of europeans. This was followed up by customs people who turned the simple task of taking a piece of paper off people into something that generated three queues that were over 50 people deep each. The point is that neither immigration or customs (gateway services) are tasked with helping to deliver the end-to-end QoS that either the consumer or the service provider (airport) wants. This creates a contention point that has no resolution because the actual governance is set up to create the problem. Immigration are tasked on letting through only desirables and don't care if you stand in a queue for an hour (or TWO hours in the case of the unluckiest person in our group).
This challenge is replicated in businesses when these gateway elements are put under IT management and are charged with cost reduction and costed as a single element. This means that their focus is on being cheap and therefore being poor.
What is the solution therefore? Well for the US immigration its probably to notice that European flights tend to have lots of Europeans on them. For businesses its to think of these gateway elements as utilities rather than as cost elements. This means that the cost for them is based on the usage and is linked back to the original consumer/provider interaction. If you want good service as its important then you need to be able to pay for a better SLA, if you don't care about the performance then you get a worse SLA.
Infrastructures need to be linked to the SLAs of the consumer/provider not have a generic SLA that attempts to cover everything and be viewed as a purely cost item in the equation, otherwise they become blockers to change and experience and you end up taking 2 hours to get through an airport and a load of pissed off users.