na-adjective
systematic; organized; organizational
Describes something done in a planned, methodical way, or something related to an organization. Often used in news and formal contexts.
彼は組織的な調査を行った。
He conducted a systematic investigation.
組織的な犯罪が増えている。
Organized crime is increasing.
体系的 also means 'systematic', but emphasizes a structured theoretical system, while 組織的 often implies practical, coordinated action.
Formed from 組織 (organization, system) + the adjectival suffix 的 (-like, -ic).