On average, IT staff put in the equivalent of an extra day of unpaid work every week, with late nights and weekend working a regular feature of life in the IT department.
Over the past two years employers have cut back their core IT staff and reduced their use of IT contractors. As a result, staff are coming under pressure to work harder and longer just to perform their day-to-day duties.
Colin Beveridge, an interim IT director who has worked in a wide range of IT departments, said long hours were becoming the norm for a growing number of organisations.
"Long hours are a problem and in my experience it is getting worse rather than better," he said. "A lot of organisations want to sweat their IT assets - in other words, people - harder and to get more out of them without necessarily paying them more money."
The TUC's research found that IT directors work an average of 9.3 hours unpaid overtime a week; IT managers work an extra 6.8 hours; and IT support staff work an extra 5.5 hours a week. Only chief executives, teachers, health professionals and agricultural managers put in more hours.
Occupational psychologists claim that sustained long hours, rather than helping the business, damage the productivity of employees and increase the likelihood of them making mistakes.
Cary Cooper, professor for organisational psychology and health at Lancaster University Management School, carried out a five-year study into the working practices of 5,000 people. He found a direct relationship between long hours, poor health and lower productivity.
"We know that long hours damage people's health," said Cooper. "We know from looking at people's perceptions that it damages productivity and damages relationships with families. In the IT business the problem is even worse because people frequently take work home.
"Different people react differently to the pressures of long hours. Some have physical illnesses, some have emotional breakdowns. Or they have inappropriate health behaviours such as excessive alcohol consumption or too much smoking."
Research by Cranfield School of Management found that UK professionals regularly put work before their personal lives, far more so than managers in other countries. In a survey conducted two years ago, it found that 75% of UK managers had cancelled pre-booked holidays to cope with the pressure of work.
Beveridge said he had often encountered IT staff working dangerously long hours. "I regularly see people who are showing signs of fatigue, not just the odd week but week-in, week-out," he said. "They are probably burning out. I have seen enough instances of this to make me think that it is storing up trouble for the future."
This can be damaging to the business, said Cooper, because tired and stressed workers are more likely to make mistakes - and in IT mistakes could lead to the failure of a costly project.
So what can businesses do? Ben Booth, IT director of market research firm Mori, said he tried to discourage his IT staff from working long hours regularly during the week. "You often have to take systems down when people are not at work at the weekend and the evening. If you need to carry out controlled and difficult operations, you cannot do it if your people are exhausted and stressed out," he said.
The Institute for the Management of Information Systems said businesses should give their senior IT staff more training in time management and delegation to combat the long-hours culture.
"IT people are not normally brilliant at delegating. A lot of IT managers have come up from the IT ranks and they have had very little opportunity to get management training," said Imis chief executive Ian Rickwood.
But for others, such as John Handby, chief executive of CIO Connect, long hours, provided they are not carried to extremes, are just part of the job.
"Some people thrive on stress and you would not become a senior IT director unless you wanted challenges," he said. "People expect to work long hours within reason, certainly when major changes are happening. In fact, I think quite a lot of them thrive on it."
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