Take steps to ensure the loss of senior staff doesn’t cause long-term disruption to your organisation, warns Rob Walker

Last week, Tesco's Colin Holmes announced his resignation just a day after the retailer appointed Philip Clarke as Sir Terry Leahy's successor.

Surprises at senior management level are like volcano eruptions: we know they happen frequently, but we're not sure when, who will be affected and what the final cost will be. Unplanned situations divert executive time away from important strategic work, can be disruptive and may last up to six months or more.

The usual reaction is for the senior team to cover as best they can, or charge a lower-level manager with stepping up to the mark, often resulting in people becoming overstretched. Neither are ideal, so why don't more organisations have better plans for predictable events? It's not all that difficult.

The top tier of leaders should only get there after being exposed to most, if not all, the key functions in the organisation. This gives them greater agility between roles, as well as a better appreciation why finance 'needs those numbers'.

It's also good to have a plan for who will cover key positions if one suddenly becomes vacant. Companies should recognise that these events are often reported negatively and can have a disruptive effect internally. Clear, fast, consistent communications are required to counter the impact.

Some take a different approach and hire an 'interim executive', a sensibly overqualified heavy-hitter to hold the fort. This can work well. 'Serial fixers' often have a hand in hiring the permanent candidate and help to bed them in before leaving the organisation in better shape.

Day rates for a senior-level interim might raise a few eyebrows though. My response is: it's time to focus less on cost and more on value. If you must focus on numbers, measure the return as you would any capital investment: on the uplift in sales figures; the fall in customer complaint costs; or the benefits of the right product on shelves, in the right quantity, at the right time.

Tesco has made huge progress under Leahy's watch. How and how quickly it fills the gap left by its fresh foods commercial director could make a big difference.

Rob Walker is a City recruiter and chief executive of BIE Interim Executive.