The team has struggled throughout the Australian Grand Prix weekend, with Pastor Maldonado describing the car as "undriveable" after qualifying.
While Coughlan said that it would be "simplistic" to describe the team as having to revert all the way to the launch specification, he accepts that the development direction has been wrong after a promising first test for the FW35.
"The philosophy is to backtrack a little bit to where we thought we had made a significant step forward," Coughlan told AUTOSPORT.
"Let's start again from there and have a look at what directions we took.
"It's a little bit simplistic, but the basic gist is that we will go back to that [launch specification] where we thought we had made a performance increase."
Williams was forced to abandon its latest exhaust/sidepod configuration after back-to-backing it with the previous version on Friday.
But although Coughlan accepted that this is an area where Williams is struggling, it is not the sole area of focus.
"There are some aspects of exhaust blowing which are quite difficult to either model or to analyse," said Coughlan.
"We were late to this game [harnessing exhaust gases for downforce], we freely admitted that we had a bit of catching up to do and several teams have had multiple goes at it over time.
"We see a direction, we see where we are good at it and we see where we have a little bit to catch up on.
"It's one of them [the areas of focus] as it is an area that reaps significant reward, but there isn't a single area that we don't constantly think of making better."
Despite the problems, Coughlan insists that there is no fundamental issue with the car that would force a redesign.
He is hopeful that progress can be made at next week's Malaysian Grand Prix, with bigger upgrades possible as early as the third round of the championship in China.
"We don't have a fundamental flexing issue [for example]," he said.
"We had a core car that worked very well, which gives us the belief that we have either gone wrong in some aerodynamic pieces or in some of the steps that we've done.
"We don't believe we have a redesign to do. We have taken a wrong direction and we will come back from that."
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