Williams team principal Jost Capito has conceded any upgrades to the FW44 across the remainder of the season will be "very minimal" with the outfit rooted to the foot of the constructors' table.
Williams has struggled to make the most of the clean sheet of paper presented at the start of the year with the all-new set of technical regulations.
The team has already switched design philosophy from a Mercedes-style disappearing sidepod concept to a more 'normal' sweeping iteration championed by Red Bull.
But with the spending cap making it difficult to develop two cars simultaneously, Williams has elected to call time on the FW44 and focus instead on the FW45.
Explaining the decision to GPFans, Capito said: “During the second half of the year, we can't expect a lot.
“We learned a lot from this year's car, but the focus goes more and more on next year's car because we don't have the capacity the big teams have.
"So, we have to start earlier on next year's car because we need longer. It is as simple as this.
“That also means we have to still sign parts off earlier. That means our development time is shorter than the big teams, and there we have to try to catch up and get better over time.
“For this, what we learned, what we can easily implement without compromising next year's car, we will put on this year's car. But that will be very minimal.”
Williams "lacking data" to improve
Williams introduced a major upgrade package at the British Grand Prix but has since suffered from a lack of running, leaving the team short on information on how to improve its set-up.
Asked directly if this "is pretty much it for the season", Capito added: “Yes, very much.
"There might be small tweaks from what we have learned because we have to understand the upgrade package.
"We haven't got a lot of mileage yet, because of the weather conditions in Silverstone, for example, and the crash at Silverstone. So we are lacking data and with that, we will improve that package.
“But the big work is already shifted to next year's car."