The phrase "highly complex process" is grammatically correct and can be used in written English.
You can use it when describing a process that is difficult to understand or has many intricate parts. Example: "The development of a new technology is a highly complex process, involving countless hours of research and experimentation."
Deciding which anticoagulant to use and for how long is a highly complex process.
However, the highly complex process of endochondral ossification is unique to bony vertebrates.
Background: Cell migration is a highly complex process, regulated by multiple genes, signaling pathways and external stimuli.
But the government cannot support the measure because a highly complex process, involving changes to laws across the Commonwealth, would have to take place.
Protein aggregation is a highly complex process resulting in formation of a variety of aggregates with different structures and morphologies.
The reaction of living tissues to foreign materials is a highly complex process that currently is insufficiently understood.
Cancer induction is a highly complex process involving hundreds of different inducers but whose eventual outcome is the same.
It could hit the odd Pynchonesque note of forensic rhapsody as some highly complex process was articulated in minute detail, but mostly it sounded like a slangy technical manual; serviceable, but short on charm, and exhausting.
We further expect that each imaging modality elucidates shared and specific dynamic brain properties underlying this highly complex process, therewith providing further important insights into learning-induced plasticity changes of the brain.
The design of machining fixtures is a highly complex process that relies on designer experience and his/her implicit knowledge to achieve a good design.
Protein folding is a highly complex process proceeding through a number of disordered and partially folded nonnative states with various degrees of structural organization.
