Why there are no single ideal or optimal logistics organisational structure?

There is no single ideal or optimal logistics organization structure ,agree that because any firm or organization after setting its mission ,vission and goals is where now logistic structure can be implimented. logistic structure can change any time or rather be flexible depending the change of organization goals.There for each organization has got its structure which is fit for its purpose , no logistic organization structure which is fi for other organization because they differ in their mission vission and goals.