When you have a requirement at short notice, the person you call on needs to be over-qualified and with the experience of having been there before. Whatever the circumstances leading to the vacant position, the business needs to continue as normal. We have experience of stepping into a business with little introduction and hitting the ground running.
Often, having someone come in from the outside in these circumstances provides an objective view of the situation from an experienced executive who is independent from the office politics that may have gone before. The assessment you get will be the one you need to hear, not just the one you are expected to want.
If you need to recruit or select a replacement, having someone on board who has been doing the job can also be a great assistance.
The Freelance FD offers a flexible and capable solution.