noun
origin; formation; how something came about
Refers to the historical or developmental process by which something was formed or came into existence. Often used for words, organizations, customs, etc.
この言葉の成り立ちを調べてみよう。
Let's look into the origin of this word.
会社の成り立ちについて話してください。
Please tell us about how the company was founded.
noun
structure; organization; makeup
Describes the way something is put together or organized, such as a system, society, or physical object. Overlaps with sense 1 but focuses more on the current composition rather than historical development.
この組織の成り立ちは複雑だ。
The structure of this organization is complex.
文章の成り立ちを分析する。
Analyze the structure of the text.
由来 also means 'origin' but is often used for this word or derivation of something, especially in formal contexts. 成り立ち emphasizes the process of formation.
構造 is a more technical term for 'structure', often used for physical or abstract systems. 成り立ち is less technical and can imply a natural or historical development.
Noun form of the verb 成り立つ (to consist of, to be formed). The kanji 成 means 'become' or 'form', and 立 means 'stand' or 'establish'.