The phrase "a challenging issue for" is correct and usable in written English.
It can be used when discussing a problem or difficulty that affects a particular group or individual.
Example: "Climate change presents a challenging issue for policymakers who must balance economic growth with environmental sustainability."
Alternatives: "a difficult problem for" or "a tough challenge for".
Scale-up of aerobic fungal fermentation processes still remains a challenging issue for the biotechnology industry.
"To some extent, elections have always been a challenging issue for our country," he admitted.
Datacentric applications are still a challenging issue for large-scale distributed computing systems.
Furthermore fuel storage is a challenging issue for portable micro fuel cell systems.
Energy and sustainable retrofit of old buildings with heritage value is a challenging issue for Europe.
Separation of ethylene from the effluent gas of oxidative coupling has been a challenging issue for several years.
Itinerary plan determines the order of locations that controllable-mobile sink(s) has to sojourn at them, where is a challenging issue especially for the resource constrained Wireless Sensor Networks (WSNs).
Firstly, a challenging issue is that suggestions for improvements are offered only for input and output measures, and intermediate measures are neglected.
It is true that device reliability including stable switching characteristics, program/erase endurance, and data retention at 85°C for 10 years at a low current of few microamperes is a very challenging issue for production.
One of the main limitations in the field is the lack of reliable tools to monitor autophagy activity in the nervous system, a challenging issue due to barriers for drug penetrance into the tissue through the blood brain barrier (BBB), and the low response of this tissue to nutrient starvation.
Resource management is a particularly challenging issue for vehicular cloud development.
