Force India says its 2015 F1 season starts properly at British GP

Delays with manufacturing of this year's chassis plus a switch of windtunnels meant the team took the decision to unveil a launch car rooted in the 2014 design before introducing a B-spec model later in the season.

Following a successful two-day test at the Red Bull Ring with further elements of the upgrade, the full package will make its competitive debut at Silverstone.

"I think it is the start of our season really," Fernley told AUTOSPORT.

"We've done the initial reorganisation and restructuring of the aero department.

"This will be the first time that we'll be able to get what we wanted to deliver out on the circuit.

"If that all works and delivers a reasonable step for us then we're very pleased."

Fernley said Friday practice at Silverstone will be busy for the team as it plans to complete its final correlation and verification processes.

"There will be a process of bringing it all together," said Fernley.

"The key thing is that we have got the mechanical side nailed and it's been signed off."

If all goes smoothly with the latest package, Fernley said the team hopes to introduce a further update after the summer break.

"It will be Spa or Monza," said Fernley. "That's contingent on everything working at Silverstone.

"We have an aggressive development programme."