Whenever the underlying process, product, or assignment changes materially, since the knowledge claim is tied to the specific facts originally documented.
Keep the claim current with the actual business
If the business adopts a new method or the employee's proposed U.S. duties change, document the change and have it reviewed rather than relying on the original filing to cover a different set of facts.
The order that works is: settle the commercial contract with the client so it describes the company's deliverable, then write the specialized-knowledge case around the employee's role in delivering it, then file. When an L-1B worker is stationed primarily at an unaffiliated worksite, the unaffiliated employer cannot principally control and supervise the worker, and the placement cannot be essentially an arrangement to provide labour for hire rather than to use the petitioner’s specialized knowledge. The specialized-knowledge maximum is five years in total, so a four-year assignment cannot be completed by someone who has already spent three years in the status, however well the project is going.