The phrase "arduous to implement" is correct and usable in written English.
It can be used when describing a task, process, or project that is difficult or requires significant effort to put into action.
Example: "The new software system is proving to be quite arduous to implement, requiring extensive training for all employees."
Alternatives: "challenging to execute" or "difficult to carry out".
Furthermore, if the protocol is overly arduous to implement (e.g., requiring substantial time or resource commitments from the clinician or their organisation) clinicians are unlikely to recruit a large number of patients (Hjorth et al, 1996; Ellis et al, 1999; Grunfeld et al, 2002; Weinberg et al, 2004; Tournoux et al, 2006; Fayter et al, 2007).
Because of its wider scope and attached financial commitments it was also more arduous to implement and perhaps also more contested by different stakeholders despite the support of the law per se, including parts of the public that still may not see the benefits of the different schemes.
Manual techniques are usually arduous to apply reliably because few structures have stable, easy to define boundaries.
There is no right or wrong way to learn a language, but there are many other ways to implement that aren't monotonous or arduous to improve your learning.
It allows to implement only small volume of repositories for the radioactive waste (mostly fission products) and to postpone the technically arduous problems of a large scale disposal of the long-lived wastes until the next millennium, i.e. up to the exhaustion of the fertile natural resources and/or the emergence of more effective technologies of nuclide separation/transmutation.
The politician, who resigned over the government's "unfair" policies in June, voiced outrage over its decision to implement a new, €11.5bn package of savage cuts over the next two years when all three parties had pledged to "renegotiate" the arduous terms of the bailout.
Policies take time to implement.
How to implement this strategy?
It remained to implement them.
Assemble teams to implement solutions.
