# Human-Centered Dynamic Service Scheduling Approach in Multi-Agent Environments
## 1 Introduction  
Service robots capable of assisting humans in their environments [1] are rapidly being developed to provide services such as household chores, in-home delivery, healthcare, and assistance in offices, hotels, hospitals, and educational environments [2, 3]. Combining robotics with innovations in computer vision, sensors, and the Internet of Things (IoT) enables robots to interpret and monitor real-world settings contextually. Improvements in speech recognition and artificial intelligence facilitate intuitive human interactions with robots [4, 5]. Accordingly, the application of human-robot interaction technology is gradually expanding to the daily service industry, and research on robots that provide highly complex and personalized services to users is in progress [6]. To provide services to users using service robots in daily life, various challenges need to be addressed. Because service robots should be able to accept and complete the user requests, service tasks must be appropriately scheduled so that they are allocated to a suitable robot and executed according to the user requirement. However, existing research on robot scheduling does not reflect these characteristics because human multi-robot system interaction was first introduced in the industry to reduce the workload of human workers and increase the productivity of manufacturing processes. In terms of efficiency, the parallel execution and synchronization of robots [7] have been a major concern for multi-robot systems. We thoroughly studied how the overall workload is distributed to ensure that the work is performed quickly. For example, [PERSON]. [8, 9] proposed a scheduling system thatdynamically changes the task distribution according to the variability of human workers so that multiple robots can safely and efficiently collaborate with humans. These studies focused on enabling industrial robots deployed in highly structured and well-controlled environments to work as efficiently as possible. Service robots, however, must be able to operate in a dynamic environment to satisfy the continuous and varying service requests of humans [1]. Moreover, humans have complex requirements for the services that they want to receive. These requirements typically include complex procedures (e.g., priority of service delivery) and guidelines that the robot should follow [10]. This results in services with sequential interdependencies. Tasks with multiple sequences are common in both natural and artificial systems. They must be consecutively completed to properly perform the entire task. Therefore, a single service can contain multiple individual subtasks that must be performed sequentially. For example, serving coffee in a kitchen may involve two separate subtasks: pouring coffee into a cup and delivering the cup to the user. If each subtask is performed by a different robot, the second robot must wait for the first robot to finish pouring coffee into the cup. In addition, we can consider a service that delivers coffee to a specific cup that the user wants. In this case, the robot should be able to bring a specific cup into the kitchen and then proceed with coffee serving. This implies that the detailed requirements of the user significantly change the sequential interdependence of the entire service. For this reason, multiple robots in a service environment need to collaborate, considering the correlation between services to fully accommodate the needs of users. This implies that the service robot must be able to dynamically accept user requests and provide services accordingly. However, current multi-robot systems do not consider the sequential relationship between services that occur according to the user's request, resulting in performance degradation or failure to fulfill. A given service can be divided into multiple sequential subtasks, each of which can vary in interdependencies owing to dynamic user requests, which are addressed by coordinating several heterogeneous robots with different capabilities.