Towards Fairness in Online Service with k Servers and its Application on Fair Food Delivery
This addresses fairness in online platforms such as food delivery, but it is incremental as it builds on existing k-SERVER variants with specific adaptations.
The paper tackles the k-SERVER problem by introducing a realistic generalization called k-FOOD to model real-world scenarios like food delivery without simplifying assumptions, and proposes an online algorithm that shows efficacy against state-of-the-art methods in experiments on real-world and synthetic datasets.
The k-SERVER problem is one of the most prominent problems in online algorithms with several variants and extensions. However, simplifying assumptions like instantaneous server movements and zero service time has hitherto limited its applicability to real-world problems. In this paper, we introduce a realistic generalization of k-SERVER without such assumptions - the k-FOOD problem, where requests with source-destination locations and an associated pickup time window arrive in an online fashion, and each has to be served by exactly one of the available k servers. The k-FOOD problem offers the versatility to model a variety of real-world use cases such as food delivery, ride sharing, and quick commerce. Moreover, motivated by the need for fairness in online platforms, we introduce the FAIR k-FOOD problem with the max-min objective. We establish that both k-FOOD and FAIR k-FOOD problems are strongly NP-hard and develop an optimal offline algorithm that arises naturally from a time-expanded flow network. Subsequently, we propose an online algorithm DOC4FOOD involving virtual movements of servers to the nearest request location. Experiments on a real-world food-delivery dataset, alongside synthetic datasets, establish the efficacy of the proposed algorithm against state-of-the-art fair food delivery algorithms.