McLaren operations director Simon Roberts reveals staff worked over Christmas break to ensure MP4-31 is on target.

Like most teams, the late decision to move the 2016 calendar forward by two weeks caught McLaren on the hop.

However, whilst Sauber has opted to miss the opening pre-season test and unveil its 2016 contender at the second test, McLaren, still hurting following its worst season in living memory, is determined to make the most of every minute of available track time.

In order to ensure the MP4-31 - which will be unveiled on 21 February - was ready on time, many staff at the team's Woking HQ forsook their Christmas break.

"We put about eight shifts of work back into the programme over a five-day period... a fantastic effort," said Roberts. "In total, there were about 110 people involved and we looked after our Christmas workers with a competitive package.

"We had a really good response, and people seemed to enjoy it too," he added, "it was a bit weird, not having all the time off, but there was a good spirit in the place. Everyone knew why they were doing it, and it really cleared the decks.

"Most pleasingly, it meant that, once we came back in the New Year, we were back on schedule and it felt like the programme had always been phased that way. It was an incredible effort."

Referring to the problems faced following the late change to the 2016 calendar, Roberts admits: "Our entire build programme wasn't lined up for that! So we knew we had a problem to solve.

"In terms of our design and engineering capacity, it's a relatively straightforward re-planning exercise, there's less time to get the work done, so everyone works a bit harder.

"But the build schedule is on a critical path, it needs to pass all the FIA safety tests and be ready for the first test, which was also brought forward. In that situation, you can't just re-plan, you need to do something different.

"To complete the new car, we're trying to chase in about 16,000 components," he adds. "Purely from a planning perspective, there's no reason why we can't build the car to deadline, it's all sequenced to come in on time and scheduled with the right lead-times - but, the Bill Of Materials isn't fixed because it develops in parallel our R&D efforts; and with that volume of parts, and the number of suppliers we have, things will inevitably go wrong."