仕組み= structure, construction, mechanism, device...etc eg: 物の仕組み= The construction of a thing. 暗号の仕組み= The structure of a secret code. 物事の構造や仕組み= The system or structure of something. So, "shikumi" means like how to work, how to consist, how to build or like that. When you wonder what's the mechanism of your PC, you can say; パソコンの仕組み(構造)はどうなっているんだろう。 "電気で動く仕組み(テレビ、電子レンジなど)"や"風力で動く仕組み(ヨット、風車など)" Is that clear now?

難しい質問ですね。 「しくみ」 is similar to 「構造」 and can be translated into the English word 'system'. I also think it means 'how something works'.