The Grove-based squad has long believed that its best chances of success in grand prix racing come from it being fully independent.
But while its decision from the start of last year to take a Mercedes gearbox, rather than produce its own, marked a big departure from its policy of the past, the team says that it will not make any further steps in the direction of becoming a customer team.
Although Haas' growing competitiveness in F1 has shown the benefits that can come from taking car parts from a manufacturer, thanks to its relationship with Ferrari, Williams remains adamant it can succeed alone.
"I think we can do what we need to do with the relationship we currently have with Mercedes for the next couple of years," explained Williams' head of vehicle performance Dave Robson.
"They provide us with some amount of hardware that's extremely good. But we are an independent team and we need to take the rest of it forwards on our own, or at least be prepared to do that.
"We'll see what the future holds for 2026 when things get shaken up again. But I don't think we want to follow a Haas model."
Despite the opportunities that smaller teams have under F1's new rules, which include a cost cap and aerodynamic development limits for top teams, Williams was left at the bottom of the constructors' championship last year.
Robson believes that while regulations are helping it close the gap, there are still plenty of legacy elements that ensure F1's former biggest spenders still have an advantage.
Asked about what he believed was holding Williams back, Robson said: "I think you can't get around the fact that the investment has been a problem.
"Although the regulations have improved in that regard, you're not going to undo the sheer amount of money the big teams have been spending for a decade.
"They've got that, whether that's equipment or knowledge, and it's got some decay time. It'll be a little bit of time before things are really reset. So that certainly is part of it."
Williams was taken over by new owners Dorilton Capital back in 2020, with the company heavily investing to make the team more competitive.
Driver Alex Albon says he remains encouraged by Dorilton's mindset, which is very much about setting out a plan for the long term, rather than believing it can make changes to deliver success overnight.
"I get to speak to the board quite often," said Albon. "And the main thing is a long-term vision. I think that's important for any kind of investment company.
"They really do see the future, they are investing, you see also with James [Vowles, new team boss]. I know in the areas that he wants to improve you have this big sense that they're fully behind everything."
