Unions and British Airways have resolved the dispute over the introduction of swipecard entry system which prompted staff to abandon their posts at Heathrow earlier this month.
The dispute has led to scenes of chaos
BBC News Online looks at why the clocking-on system was so controversial in the first place.
A spokeswoman for the Amicus union said the clocking on and off system - known as automatic time recording (ATR) - would in itself make little difference to customer services staff, who already had to be signed in and out by their duty managers on paper.
The real concern for workers was what the data collected by the system might be used for - and the fact it had been "imposed" on staff without union agreement, she said.
The Amicus representative, who did not want to be named, claimed that by introducing ATR, BA was taking the first step towards introducing a network of electronic systems, known as Integrated Airport Resource Management (iARM).
"ATR is a side issue. The fear is that under iARM they will take the data from the ATR to restructure people's rotas, and introduce annualised hours and split shifts - for example, getting people to come in for two hours, going home for two hours, then coming back in again.
"At the moment, staff know their rotas about three months in advance. They're able to swap shifts and plan family commitments, such as childcare and holidays."
With the introduction of ATR - and any systems which might follow it - staff are worried they may be called in at short notice during busy times, or sent home during quiet periods.
"Annualised hours would mean staff having to work at short notice - for example, if there were delays - and having to bid for leave," the Amicus representative said.
"We have a very, very large number of women that work at Heathrow, because it's so flexible.
"We have lots of people doing 'tarmac transfers' of babies and children - they can come into work at four in the afternoon and hand over the children to their partners.
"It works because people know what they're doing months in advance, and are able to make plans."
A BA spokeswoman said the airline was looking at moving all of its operations from paper-based to electronic systems over the next five years, and said iARM had been identified as a "suitable" way of managing staff.
But she said that the introduction of the swipecard entry system was not connected to this, and that iARM consisted of a variety of systems which operated independently of each other.
"We have given a guarantee to staff that ATR is not being used as a step towards annualised hours.
"The trouble is, we have a large number of people often working very complicated shifts.
"ATR will enable us to more accurately record shifts, and over time, make our rostering system more productive.
"We are keen to give staff as much advance information as possible about shifts. This system is already used by our ground handling staff."
The spokeswoman denied ATR would mean large changes to working patterns, as managers were already well aware of what the busy periods were, and rosters were put together accordingly.
She added that BA had been "working closely" with the unions for 12 months to try to reach a resolution over the introduction of ATR.