No plan survives contact with the enemy

No plan survives first contact with the enemy.

No plan survives the first encounter with your enemy, so why bother to make one?

No battle plan ever survives contact with the enemy.

No plan of battle survives contact with the enemy, and time is the ultimate opponent.

They say no plan survives first contact with implementation. I’d have to agree.

Kein Operationsplan reicht mit einiger Sicherheit über das erste Zusammentreffen mit der feindlichen Hauptmacht hinaus.

No business plan survives first contact with customers.

The first casualty of any battle is the plan of attack.

My whole life has been a battle lost on the map. Cowardice didn't even make it to the battlefield, where perhaps it would have dissipated; it haunted the chief of staff in his office, all alone with his certainty of defeat. He didn't dare implement his battle plan, since it was sure to be imperfect, and he didn't dare perfect it (though it could never be truly perfect), since his conviction that it would never be perfect killed all his desire to strive for perfection. Nor did it ever occur to him that his plan, though imperfect, might be closer to perfection than the enemy's. The truth is that my real enemy, victorious over me since God, was that very idea of perfection, marching against me at the head of all the troops of the world - in the tragic vanguard of all the world's armed men.

No business plan survives its first contact with customers.

On finding the enemy has notice of your designs, you must immediately alter your plan of operations. Consult with many on proper measures to be taken, but communicate the plans you intend to put in execution to few, and those only of the most assured fidelity; or rather trust no one but yourself. (General Maxims)

[ The war is not don so long as my enemy lives. ]

Project planning isn’t about avoiding changes, it’s about controlling them. No project plan ever survives contact with the enemy.