We derive the first performance guarantees for a combinatorial online algorithm that schedules stochastic, nonpreemptive jobs on unrelated machines to minimize the expectation of the total weighted completion time. Prior work on unrelated machine scheduling with stochastic jobs was restricted to the offline case, and required sophisticated linear or convex programming relaxations for the assign...

In this paper, we address the problem of parallel batching of jobs on identical machines to minimize makespan. The problem is motivated from the washing step of hospital sterilization services where jobs have different sizes, different release dates and equal processing times. Machines can process more than one job at the same time as long as the total size of jobs in a batch does not exceed th...

We derive the first performance guarantees for a combinatorial online algorithm that schedules stochastic, nonpreemptive jobs on unrelated machines to minimize the expectation of the total weighted completion time. Prior work on unrelated machine scheduling with stochastic jobs was restricted to the offline case, and required sophisticated linear or convex programming relaxations for the assign...

In inventory, the utility of the deteriorating items decreases with time. The degree of deterioration of product utility can be treated as penalty cost in the inventory replenishment system. In this paper, we present EOQ model for those perishable products, which do not deteriorate for some period of time and after that time they continuously deteriorate with time and loose their importance. Th...

PURPOSE The purpose of this study was to investigate (a) whether certified nursing assistants (CNAs) are more committed to nursing home jobs when they perceive their jobs as enhanced (greater autonomy, use of knowledge, teamwork), and (b) whether CNA job commitment affects resident satisfaction. DESIGN AND METHODS A qualitative exploration of management philosophy and practice and of CNAs' vi...

We consider a scheduling problem with two parallel machines to minimize the sum of total weighted completion time and total machine time slot cost. In this paper we focus on the case of the constant or linear decreasing sequences of time slot costs. We suggest an exact pseudopolynomial DP algorithm for the case of arbitrary integer processing times of jobs. If all jobs have unit processing time...

INTRODUCTION We investigated the relationship between frequency of exacerbation and duration and change in functional status, as measured by the BODE index in chronic obstructive pulmonary disease (COPD) patients. METHODS This was a longitudinal cohort study of 56 patients with moderate to severe COPD. Body mass index, spirometry, Modified Medical Research Council (MMRC) dyspnoea score and si...

We consider an online scheduling problem in a parallel batch processing system with jobs in a batch being allowed to restart. Online means that jobs arrive over time, and all jobs’ characteristics are unknown before their arrival times. A parallel batch processing machine can handle up to several jobs simultaneously. All jobs in a batch start and complete at the same time. The processing time o...

This study considers outsourcing decisions in a flexible flow shop scheduling problem, in which each job can be processed by either an in-house production line or outsourced. The selected objective function aims to minimize the weighted sum of tardiness costs, in-house production costs, and outsourcing costs with respect to the jobs due date. The purpose of the problem is to select the jobs tha...