I had a production schedule for food processing. As same facilities is used,
the different products is run in sequence in batches below timing

A B C D
E
Next Food Next food Next Food Next
Food
5 Current Product Ham Cheese Bread Jam
6 Ham - 2min 4min
3min
7 Cheese 5min - 3min
2min
8 Bread 2 min 4min -
1min
9 Jam 5min 3min 1min -

How do I determine the sequence for the above food order that will minimise
the time taken for exchange products.