The phrase "unachievable objective" is correct and usable in written English.
It can be used when discussing goals or targets that cannot realistically be attained.
Example: "Setting an unachievable objective can lead to frustration and demotivation among team members."
Alternatives: "impossible goal" or " unattainable target".
Congress is actively seeking to make a deal on the nuclear issue impossible by imposing unfeasible red lines, setting unachievable objectives — and depriving the executive branch of the freedom to bargain.
While not contradicting intelligence assessments suggesting that Al Qaeda remains a major threat with a strong presence in the tribal areas of Pakistan, the report says that the group "may decay sooner" than many experts have assumed because of severe weaknesses: "unachievable strategic objectives, inability to attract broad-based support and self-destructive actions".
Project, are presented to illustrate that sliding base isolators can be used to meet otherwise unachievable design objectives.
An improvement in infrastructure requires substantial investment and seems an unachievable short term objective in Kathmandu.
The If campaign, by working with David Cameron and the leading representatives of global capitalism, is sustaining the very food system that makes its objectives unachievable.
African civil society rejected the alliance as part of a "new wave of colonialism", and War on Want has accused the If campaign of being too close to power "sustaining the very food system that makes its objectives unachievable".
I have reached the conclusion that, in the circumstances, the Syria Heritage Foundation should be wound up, its aims and objectives being unachievable in the near future.
Study of sustainable health-protective behaviour indicates that numerous difficulties make this aim unachievable.
'Core' groups found their development objectives to be unachievable without the collaboration of others.
