"It was the case in certain areas, but we were caught out in three principal ways. The first was a significant reliability problem with the pistons. We had another part inside the PU electronics that we could not put our finger on and it continued to be a source of problems.

"We arrived at the first winter test [of 2015] believing that we had made a big step forward between seasons. We genuinely thought that we had done a good job," Taffin explained.

Remi Taffin, Director of Operations, says the French manufacturer effectively tripped themselves up in 2015 by being too hasty in their bid to close the gap to the front. He is confident a subsequent 'return to basics' will produce a much clearer direction for the future.

"The final element is that we braked so late for 2015, taking decisions until the last possible moment. The specification of PU for the first race was determined very late in the day and quite simply we braked too late, and we weren’t ready.

"We wanted to make up the gap so badly that we pulled the rug out from under our own feet... but this particular cocktail of problems did allow us to learn a lot and make sure that the same issues will not reoccur in the future.

"We end the season much more knowledgeable and information-rich - unfortunately we did not get the results we wanted, but everything has allowed us to prepare in the short term for 2016 and longer term beyond that.

"We are in much better shape now than we were at this point last year, for sure."

Taffin said Renault will also step up their work with highly-regarded Ilmor Engineering to aid the development of their power unit.

"They [Ilmor] were able to bring different concepts to the table, such as a different combustion concept, and now we will continue with them into 2016," Taffin said.

"We will continue to develop a lot in-house but with partners such as Ilmor we have a greater bandwidth and a richer experience and expertise. We did not see the full extent of the collaboration in 2015 for various reasons, but now they are under our control and we have a clearer direction we should see this more in 2016 and beyond."

Renault confirmed earlier this month that they will return to Formula One racing as a works entrant in 2016, having agreed a deal to acquire a controlling share in Lotus.