Source: German Association of the Automotive Industry (VDA)
The figure above outlines the timeline of a standardization process within ISO. The process is initiated with a New Work Item Proposal (NWIP, or NP) which enters into the stage of a Committee Draft (CD) after a timeframe of 12 months. As soon as the CD is available (only to the technical experts who are members of the standardization body), a balloting phase of three months is organized during which the experts can provide editorial and technical comments for the CD document. As soon as the commenting phase is finished, the collected comments are usually resolved during online web conferences.
The result will be drafted into a Draft for International Standard (DIS) (if no second CD is needed in between CD and DIS). At this stage, the document is publicly available and can be purchased online. Another commenting and balloting phase will be conducted for the DIS stage, similar to the process for the CD stage.
The last stage before finally publishing the new draft as an International Standard (IS) is the Final Draft for International Standard (FDIS). This is an optional stage which can be skipped if there is no negative DIS ballot. The FDIS can again be commented on by the experts, but no more technical comments are allowed, only editorial ones.
As you can see from the figure, an ISO standardization process can take from 24 up to 36 months in total.