The phrase "understandable frustration" is correct and can be used in written English.
It is typically used to describe a feeling of frustration that is reasonable or easy to comprehend. Example: Despite multiple attempts, she couldn't get the printer to work and unleashed her understandable frustration by slamming her fist on the table.
Out of understandable frustration with the Mets organization, it decided to drop out of the event altogether.
They were just as worn out, but they needed a goal more, and Slaven Bilic was sent off in stoppage time for showing his understandable frustration.
Frustration with the police – understandable frustration, given the mimsy procedural talk we've all become accustomed to – led to his making an understandable mistake.
When those who make criticisms of foreign policy get accused of creating the mood music for terrorism, there is understandable frustration and despair.
It's all done with great style and skill, if an understandable frustration in hindsight on behalf of the third party, the viewer, to get at the objective truth.
And then after the briefest of moments, we again find the world sympathizing with the oppressed Palestinians and their "understandable frustration" with Israel's "refusal" to make the concessions for peace.
Conte has understandable frustrations that he could not add more significantly to the squad he was handed over by the caretaker, Guus Hiddink, after Mourinho was ousted.
The public are rightly concerned about what this means for them and their families and this shows up in the opinion polls where they express their understandable frustrations.
Writing for the majority, Justice Anthony M. Kennedy said, "Arizona may have understandable frustrations with the problems caused by illegal immigration while that process continues, but the state may not pursue policies that undermine federal law".
The diplomat, who declined to be named because he said Syrians, rather than foreigners, should be describing their decisions, dismissed the complaints as understandable "frustrations and rivalries" within the opposition movement.
The Telegraph was more concerned about the need to beat Labour, concluding: "Ukip currently enjoys a certain degree of momentum, given pace by the understandable frustrations that many voters feel with politics-as-usual and the complexities of government that make change sometimes slow to see.
