Why the plan runs backwards
A forward plan asks "what do I do next?" A backward plan asks "what is the last possible day for this?" Only the second one finds the problem while there is still time to fix it.
Work forwards and the standards certificate looks like a task somewhere in the middle. Work backwards from the sailing date and it becomes what it really is: a thing that must be finished before a specific day, in another country, by somebody who does not work for you.
The three lead times that surprise people
Registering a regulated product takes months, not weeks. Not the shipment, the product itself. If you are importing food, medicine or cosmetics for the first time, this dwarfs everything else on the plan.
The standards certificate has to be inspected and issued where the goods are made. There is no version of this that happens after loading.
Raising the duty money. It is often the largest single payment, it falls due within days of arrival, and every day it is late is charged on three separate meters.
What to do with the plan
Send it to your supplier. Half these dates are things they do, not things you do. A supplier who has exported to your country before will confirm them immediately. One who has not will go quiet, and that silence is worth discovering now.
Put it in your calendar, not a document. A plan in a file is a plan you will read once. The reminders are the point.
Rebuild it when the sailing moves. Sailings move constantly, and when the ship date changes every date before it changes too. Come back, change the one date, and take the new file.
Where this plan is deliberately vague
Free days, transit times and agency lead times vary by carrier, route, product and country, and a confident number here would be a false one. The dates that come from rules are firm. The dates that come from other people's schedules are estimates, and the plan says which is which.
Anything marked must happen stops the shipment if it is missed. Everything else delays it. That is a real difference and it should change what you chase first.