Vol.:(0123456789) Computing (2021) 103:1353–1389 https://doi.org/10.1007/s00607-021-00935-9 1 3 REGULAR PAPER An improved list‑based task scheduling algorithm for fog computing environment R. Madhura 1  · B. Lydia Elizabeth 2  · V. Rhymend Uthariaraj 1 Received: 10 December 2019 / Accepted: 2 March 2021 / Published online: 27 March 2021 © The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature 2021 Abstract A high-performance execution of programs predominately depends on the efcient scheduling of tasks. An application consists of a sequence of tasks that can be rep- resented as a directed acyclic graph (DAG). The tasks in the DAG have precedence constraints between them and each task has a diferent timeline on diferent proces- sors. In this paper, a new list-based scheduling algorithm is proposed which sched- ules the tasks which are represented as a DAG structure. The main focus of this algorithm is to schedule the tasks to the suitable processing node in fog environment as the fog nodes have limited processing capacity. The assignment of tasks on the fog node should consider both the computation cost of the node and the execution fnishing time of the node. The proposed algorithm has three phases. (1) the level sorting phase, where the independent tasks are identifed (2) in the Task prioriti- zation phase the proposed algorithm assigns priority to the task which has more successors so that more tasks in the next level can start their execution and (3) in the task selection phase a balanced combination of local optimal and global opti- mal approach is considered to assign a task to a suitable processor which further enhances the processor selection phase results in minimizing both the makespan and overall computation cost of the processors. Extensive experiments are carried out using randomly generated graphs and graphs from the real-world to analyze the per- formance of the proposed algorithm. The results show that the proposed algorithm outperforms all other well-known algorithms like predict earliest fnish time, het- erogeneous earliest fnish time algorithm, minimal optimistic processing time, and SDBBATS in terms of performance matrices like average scheduling length ratio, speedup, and makespan. Keywords Directed acyclic graphs · Makespan · List scheduling · Fog environment · Task scheduling Mathematical Subject Classifcation 68W10 · 68W15 * R. Madhura madhuraa@mitindia.edu Extended author information available on the last page of the article