Past, Present and Future are considered to be three temporal and logical
concepts which are well defined by human beings for their existence and growth.
We, as human beings, have the privilege of using our intelligence to mentally
execute an activity before physical occurrence of the same in the real world.
Knowledge of the past, aplomb of present and visualisation for the future
correspond to three concepts such as look-back, look-at and look-ahead
respectively in real life as well as in diversified domains of computing.
Look-Ahead(LA) deals with the future prediction of information and processing
of input to produce the output in advance. In this article, our main objective
is to learn, understand and explore the concept of LA and design novel models
as solution for real world problems. We present three well known algorithmic
frameworks used in practice based on availability of input information such as
offline, online and semi-online. We introduce interesting real life
applications and well known computing problems where LA plays a significant
role for making a process, system or algorithm efficient. We define new types
of LA and propose a taxonomy for LA based on literature review for designing
novel LA models in future. Using the concept of LA, We identify and present
many interesting and non-trivial research challenges as future potential
research directions. Intuitively, we observe that LA can be used as a powerful
tool and framework for future researchers in design of efficient computational
models and algorithms for solving non-trivial and challenging optimization
problems.

通过对未来信息的预测和处理提前生成输出，Look-Ahead（LA）在实际中具有重要作用。本文介绍了三种实践中使用的算法框架，包括线下、线上和半在线方法，并提出了基于文献综述的 LA 分类。此外，本文还识别和提出了未来潜在研究方向中的许多有趣且非平凡的研究挑战。