3 It takes six hours for a contract laundry to wash, dry and press (in that order) a batch of overalls. It takes 3 hours to wash the batch, 2 hours to dry it and 1 hour to press it. Usually, each day’s batch is collected and ready for processing at 8.00 a.m. and needs to be picked up at 4.00 p.m. The two people who work in the laundry have different approaches to how they schedule the work. One schedules ‘forward’. Forward scheduling involves starting work as soon as it arrives. The other person schedules ‘backwards’. Backward scheduling involves starting jobs at the last possible moment that will prevent them from being late.

(a) Draw up a schedule indicating the start and finish time for each activity (wash, dry and press) for both forward and backward approaches.

(b) What do you think are the advantages and disadvantages of these two approaches?