The clock struck 10pm, causing John to realise that it was going to be another late finish. One more piece of analysis was needed to support a critical decision that had to be made in the morning.

The spreadsheet in front of him had already been rebuilt twice because of inconsistencies in the underlying data. And emails continued to arrive asking for ‘just one more cut’ of the numbers.

What concerned John was not the workload. It was the fact that he was starting to make mistakes. He was forgetting facts he would normally remember. He was losing track of details and increasingly relying on his team to cover areas he would once have handled himself. The pressure was beginning to impact his capability.