## 2 Literature Review
[PERSON] and [PERSON] considered a dynamic flexible flow shop scheduling that simultaneously measured the schedule efficiency by the total weighted tardiness and the schedule stability by the absolute deviation of completion times [43]. The considered stability criterion measures the difference between the completion time of the jobs before and after the rescheduling. Indeed, when the sequence is disrupted, the initial jobs completion times may change and will be replaced by real completion times obtained after the rescheduling. Moreover, there are also several works dealing with the stability measure in the rescheduling problems, such as the starting time deviation and the total deviation penalty [42], the starting time deviation [45], the amount of operations and the starting times operations have been altered [46], the absolute positional disruption, the positional disruption and the absolute completion time disruption [47], the total sequence disruption [48], the maximum time disruption (change of delivery times of jobs to customers) [49] and the rescheduling cost [50]. Most of these works consider the starting or the completion time deviation as a criterion to evaluate the schedule instability. However, the movement of the important orders is not considered in these stability measures. Assigning the weights to the stability criterion, penalizes more largely the movements of the important or the urgent operations. Thus, it will be difficult to change the position of the high priority operations. To the best of our knowledge, there is only few papers that consider the weights on the stability measures. To bridge the gap, this work investigates a new stability measure by considering the _TWCTD_ as a stability criterion. The predictive-reactive rescheduling strategy is the most used strategy to reschedule the jobs in response to disruptions [61]. The principle of this strategy is based on two steps. The first one is the predictive step. It consists in creating an initial schedule. The second one is the reactive step. It consists of revising the established schedule, at each time, a disruption occurs, in order to minimize its impact on the schedule performance [8]. Several researchers in the literature have adopted this strategy. For instance, [PERSON] et al. recently implemented in a single machine rescheduling problem, a proactive-reactive strategy consisting in the first phase to use tentative information (release dates, processing times and due dates) to construct a set of feasible schedules [63]. Then, In the second reactive phase, the schedule is progressively built as the horizon rolls forward. [PERSON] and [PERSON] treated a single machine rescheduling problem where they used a predictive-reactive strategy to handle the occurrence of uncertain future jobs. Their strategy consists to determine the amount of planned idle time for uncertain future jobs and their positions as a predictive step [64]. Then, when a disruption occurs, the schedule reacts through including the new jobs in the idle time. [PERSON] et al. treated a predictive-reactive approach of surgery scheduling problem for a single surgical suite, subject to random emergency surgeries [65]. The authors generated a primary schedule to optimize the schedule efficiency. Then, a slack time is inserted to introduce an emergency surgery when it occurs. In this work, we have used Predictive-reactive rescheduling strategy but acting differently from previous works. Firstly, we solve an initial problem with the objective of minimizing the _TWWT_. After occurrence of a disruption, the objective becomes to minimize a new criterion combining simultaneously the schedule efficiency and the schedule stability, with the _TWCTD_ as a stability measure. In addition, we have associated these two criteria by a coefficient \(\alpha\), for helping the decision maker to find an overhead between the two problem aspects. Several authors have opted to model the problems of operating room rescheduling as machine rescheduling problems.