Williams says its recent poor form in Formula 1 cannot be put down to its decision not to purchase listed parts from a front-running team such as Mercedes.
Having finished last in the constructors' championship each of the last two years, Williams slumped to its worst-ever F1 season in 2019 as it scored just a single point.
Midfield rivals such as Haas and, more recently, Racing Point have looked to boost their fortunes by taking customer parts from Ferrari and Mercedes respectively.
Racing Point turned heads with its 2020 car that was based heavily on last year's Mercedes championship-winning, prompting the RP20 to be dubbed a 'pink Mercedes'.
But Williams deputy F1 chief Claire Williams stressed the team would not be following that approach, making clear her desire for the squad to remain as independent as possible.
"I've always been really clear on where Williams stands around being an independent constructor and how proud we are of that. We're in this sport based on what we do," Williams said.
"But when we get it wrong, that's our fault. And when we get it right, we can take credit for that. So that is hugely important to who we are.
"We've been successful with the business model that we have in the recent past. We were very successful in 2014, '15, '16 and '17. It's just the past two years.
"It's not because we don't have a Mercedes, that's coloured pink that we're not doing very well."
Racing Point technical chief Andrew Green said previously he was surprised more teams had not followed the approach of bringing in more listed parts.
While Williams said the likes of Racing Point were "entitled" to do so as it did not breach the regulations, the differing business models meant not every team had the need to do so.
"That's their choice. They have a very different setup to that which we have," Williams said.
"We have a full manufacturing and operations department within the team, and I don't have any intention to change that.
"They don't have that capacity, they don't have that bandwidth. So it makes sense for them as a business model.
"We all have very different business models up and down the pit lane, and they all work for you as they do, and you make those choices."