A scheduling problem is characterized by the properties of the jobs, the properties of the machines, the properties of the processing constraints and the optimality criterion. The properties of the jobs involve the processing time of the jobs, the release dates, deadlines and priorities. The properties of the machines are the number of machines, processing speeds of the machines and machine con...

Using a sample of male and female workers from the 1992 Employment in Britain survey we estimate a generalised grouped zero-inflated Poisson regression model of employees’ selfreported lateness. Reflecting theoretical predictions from both psychology and economics, lateness is modelled as a function of incentives, the monitoring of and sanctions for lateness within the workplace, job satisfacti...

In this paper we address the problem of planning a temporary storage area in a shampoo making system. Everyday, the packing service of the company, which gathers several packing lines, transmits plans of orders to produce (also called batches) to the making service. Each plan corresponds to the work that will be performed by one packing line for the next production horizon. A batch, which consi...

We study single machine scheduling problems, where processing times of the jobs are exponential functions of their start times. For increasing functions, we prove strong NP-hardness of the makespan minimization problem with arbitrary job release times. For decreasing functions, maximum lateness minimization problem is proved to be strongly NP-hard and total weighted completion time minimization...

In this paper we consider the open shop scheduling problem where the jobs have delivery times. The minimization criterion is the maximum lateness of the jobs. This problem is known to be NP-hard, even restricted to only 2 machines. We establish that any list scheduling algorithm has a performance ratio of 2. For a fixed number of machines, we design a polynomial time approximation scheme (PTAS)...

This paper considers a scheduling problem in which a single operator completes a set of n jobs requiring operations on two machines. The operator can perform only one operation at a time, so when one machine is in use the other is idle. After developing general properties of optimal schedules, the paper develops e cient algorithms for minimizing maximum lateness. The algorithm has time complexi...