## 1 Introduction  
In this research, we will present an advanced Decision Support System (DSS) capable of human-centric management of operational procedures which, in most instances, are characterized by their intricate nature [1]. These processes are sequential or parallel and distinctly well-defined and they constitute a mission in its entirety. According to specialists in operational terminology, a mission is defined as a set of interconnected or not operational procedures. These processes are intricately linked and heavily reliant on large-scale input datasets and information. Furthermore, in this study, a _complex mission_ is defined as a scenario within an environment that encompasses a multitude of actors and sub-actors as integral components of a system. This definition of complexity typically refers to scenarios involving extensive input data integration derived from both internal and external sources, coupled with a significant number of operational procedures or processes. Such missions demand an advanced DSS meticulously engineered to proficiently manage their procedures, ensuring the effective completion of the missions. The DSS necessitates a well-structured design to function correctly in aiding the accurate planning and real-time execution of a mission within the system. It requires a structure for handling the necessary input data before entering in the system. This study introduces a novel SS sub-component, the _Complex Mission Support System_ (CMSS or CMS system). Furthermore, this study proposes a new Decision Support System (DSS) scheme, in which a CMSS is interconnected to an Information System (IS) and the overall architecture constitutes a DSS. The CMS system is a kind of specialized system which resides in the intersection of DSSs and ISs (see Figure 1). The structure of DSSs, including some indicative functions, encompasses:  
* _Decision Support System (DSS):_ This system plays a pivotal role in the design, monitoring, and real-time execution of missions. It includes a range of functionalities such as (a) designing the mission's blueprint, outlining objectives, strategies, and resources, (b) monitoring the mission's progress, ensuring adherence to the predefined plan, and (c) facilitating real-time adjustments and decision making during mission execution to respond to operational conditions of a dynamic nature. * _Information System (IS):_ This system is integral to data/information management, with functionalities including (a) managing input and output data/information, ensuring the accuracy and relevance of data used in decision-making processes, (b) handling data/information, encompassing storage, retrieval, and processing operations, (c) responding to Requests for Information (RFIs), ensuring timely and accurate dissemination of information, (d) implementing a computationally efficient classification of data/information to enable efficient categorization and retrieval, and (e) categorizing data/information thematically, which facilitates easier access and analysis for specific mission aspects. * _Complex Mission Support System (CMSS):_ This kind of system is designed for executing intricate missions, with features such as (a) producing detailed records of actions taken (log files), providing a comprehensive procedure footprint for efficient analysis, (b) predicting new intermediate (crucial for the mission) actions' nodes, facilitating proactive planning and resource allocation, and (c) executing operational procedures efficiently, ensuring the seamless implementation of mission-critical tasks. At this point, it is deemed appropriate to mention that the complexity of the procedures of CMSSs has been a significant challenge for IT engineers because it often exceeds the IS's limits due to the inability of the ISs to organize and handle further incoming information [2].