〜次第

Says that the speaker will do something immediately once the preceding event is completed; typical of business speech, announcements and emails. The second clause must refer to the future — it cannot describe a past event, and it usually expresses the speaker's will, a request or a promise (〜ます、〜てください). Unlike 〜たらすぐ, it is not used with natural phenomena or accidental events.

• 雨がやみ次第、出発します。

  あめがやみしだい、しゅっぱつします。

  We will set off as soon as the rain stops.

• 日程が決まり次第、ご連絡いたします。

  にっていがきまりしだい、ごれんらくいたします。

  I will contact you as soon as the schedule is decided.

• 商品が入荷次第、メールでお知らせします。

  しょうひんがにゅうかしだい、めーるでおしらせします。

  We will notify you by email as soon as the goods arrive in stock.