When a seller lists his product on any MP,
Then the seller is required to provide an SLA time (service level agreement) that the particular sku's order will be shipped in the given duration once the order is received for that particular sku.
Express fetches the SLA time given by a seller to the MP and show the order which are about to breach their sla or has already breach their SLA.
**Remember to attain a higher rating with the MP, a seller is required to minimize the orders which breaches their SLA**