expression
as soon as ... is completed; as soon as ... is ready; as soon as one can
Used after a verb stem or noun to mean 'as soon as that action is completed' or 'as soon as the condition is met'. Often used in business or scheduling contexts.
準備が出来次第、ご連絡いたします。
We will contact you as soon as preparations are complete.
書類ができ次第、提出してください。
Please submit the documents as soon as they are ready.
次第 is a suffix meaning 'as soon as' or 'depending on'. 出来次第 is a fixed expression combining 出来 (completion) with 次第.
Compound of 出来 (deki, 'completion') + 次第 (shidai, 'as soon as').