The phrase "a design mistake" is correct and usable in written English.
It can be used when referring to an error or flaw in a design process or outcome.
Example: "The product failed to meet user expectations due to a significant design mistake that went unnoticed during development."
Alternatives: "a design error" or "a design flaw".
Those toys, though produced in China, were recalled because of a design mistake by Mattel.
In those remarks, Mr. Debrowski clarified that many of the units recalled this summer were magnetic toys that, though produced in China, were recalled because of a design mistake by Mattel.
A design mistake in the database has it listing single character names, such as 金 Jin, 文 Wen or 海 Hai as alternative names.
It's quite difficult to redress an Active Directory design flaw once it reaches the deployment stage, and Active Directory consultants with experience acknowledge that a design mistake is costly in terms of money, time, and lost productivity and it certainly doesn't help the confidence factor.
About 27,000 absentee ballots cast by early voters can't be digitally scanned because of a design mistake.
Assuming this was a design mistake, and there was no intent to deceive the audience, this is a common mistake that many designers make.
In what was probably an unfortunate design mistake, the tube-top portion of Williams's outfit kept slipping down.
While these continual changes can sometimes make things more confusing, the beta program could potentially head off any design mistakes, uncover issues Twitter itself may have missed, and help Twitter harness that sort of viral development in a more focused way.
Not to mention, I am a bit of a perfectionist when it comes to my work, so I will work very carefully not to make any design mistakes.
Perhaps this unseemly stampede might lead Congress to reconsider its original design mistake.
This analysis helps designers to detect design mistakes and to provide effective mechanisms for fault tolerant systems.
