Realising that nothing can stem the rising tide of consumer devices flooding into the workplace, most smart CIOs have decided against the King Canute option and are instead they are smiling and welcoming in these alien devices, albeit through gritted teeth.

Bring your own device (BYOD) – the trend for staff to use their own smartphones, tablet and laptops for work is one of the biggest headaches for CIOs right now. Looking at it from a numbers point of view, BYOD doesn’t make sense, as one CIO told me yesterday.

This echoes what many other tech chiefs have said – that you can’t build a business case for bring your own device based on standard metrics (indeed, research suggests that less than one quarter of organisations make a strong business case for allowing staff to use their own hardware in the office).

Sure, you’ll save some money because you don’t have to buy hardware for staff, but you’ll end up providing some form of support to a much wider range of devices, and you may well end having to upgrade your corporate network and beef up security to deal with the increased traffic that comes from staff touting more powerful devices. And then add in the HR and finance overhead, plus the cost of the mobile device management software you’ll need, too.

When faced with this pile of cost and complexity, suddenly shelling out for a desktop or so-so laptop every five years doesn’t seem like such a bad deal for many CIOs. Alas, that’s not going to stop BYOD because those metrics are irrelevant.

True, there’s a (marginal) case to be made the staff are happier and more efficient if they can work on their own devices. It also means that they can use the equipment they think is best for the job, which can trump the one-size-procured-for-all philosophy of the corporate chequebook.

But really, most businesses don’t need to build a business case for BYOD because it’s already happened. Building a business case for BYOD would just be building a business case for the sun to rise in the morning. It’s going to happen anyway.

In some respects the rise of bring your own device is a crushing defeat for the CIO and the IT organisation, because they’ve been so easily outmanoeuvred by staff and their desire for shiny gadgets.

From another point of view it’s the workers that have overplayed their hand – for decades the employer has been responsible for providing the tools employees’ need to do their jobs and now that burden (which can easily run into thousands of pounds) is now dumped on them.

And CIOs are implementing draconian policies to ensure security – if you lose your device, or leave the organisation, they’ll wipe it. This could take the shine off of BYOD unless it’s well communicated to staff – and perhaps means that the CIO will have the last laugh, after all.