BBC bosses lacked the technical knowledge "to challenge progress on DMI from a technology perspective" - knowledge "which could have provided a broader, more robust oversight".
These are not new objectives but they have been challenging to progress when the major concern of many councils has been with rationing scarce public resources.
Peripheral nerve repair across long gaps remains clinically challenging despite progress made with autograft transplantation.
Learning to play an instrument is challenging; the progress in the early stages is slow, and the exercises that help you learn are boring and tedious.
Supreme Leader Ayatollah Ali Khamenei spoke out on the protests for the first time Tuesday, blaming the regime's international "enemies" for challenging the "progress of the Iranian nation".
But for all the threats, risks and challenges, progress has been made over the past 15 years.
Parallel to taking such actions, we also need to shine a light on how opponents of LGBT equality are defending marriage bans as federal court challenges progress in Virginia, North Carolina, South Carolina, Tennessee, Kentucky, West Virginia, Alabama, Mississippi, Arkansas and Louisiana.
Despite challenges, progress is being made.
But there are numerous social forces and tendencies, such as those outlined above, that challenge progress towards constructive change.
Despite these challenges, progress is being made in incorporating ontologies and ontology-annotated data into machine learning and data mining algorithms.
