On certain days business can feel like a war of attrition. Meetings, calls and emails bring an endless stream of difficulties: customers going broke and not paying their bills, rivals poaching staff, property disputes, suppliers demanding price increases, employee grievances, frauds, accidents, collapsing deals and so forth.

It could be argued that struggle is at the heart of enterprise: in a free market, competitors battle it out to seize share from others. Management talk is full of phrases such as “aggressive expansion”. In among that melée a leader is tasked with generating a profit. Why on earth would such an activity not be constant combat? Any entrepreneur should be good at coping with the stress that inevitably arises from such conflict and striving. But how does one put the various challenges into proportion? Which are trivial and which are a crisis?

In the 1960s, two psychiatrists invented a table called the Holmes-Rahe Life Stress Inventory, which rated 43 events as factors in causing illness, going from 100 points for the death of a spouse to 11 for a parking ticket. It includes obvious tragedies and problems such as divorce, jail and personal injury. So I have devised a special stress rating for business owners and bosses – the Johnson-FT Entrepreneur Life Stress Inventory.