Manage Payload Data Ground Segment Validation and Operation using an hybrid MBSE approach Ivan Famoso, Stefano Tatoni Rhea Group Spa Frascati. Italy Copyright © held by the author Abstract— After the Production stage the PDGS system is block, interfaces, testing procedures, data type, documents. verified and deployed in operation. If a traditional document Model can be populate starting from an editable Word based approach has been used, hundreds of documents has been Document (if not available the SE can use a pdf/doc written and the cost to change the pattern is very high. The aim converter) or Excel Document. The SE needs to properly of this paper is to present an “Hybrid MBSE” approach that can reformats documents so that key information is marked with a helps the SE in managing the Validation and Operation processes. This approach focus on the modelling of key proper style or header and use EA Office MDG Plugin (after information useful for managing Space Administration Phase E the configuration of a proper template), to automatically in a most effective way. Overall documents generated during the import design elements and relations. SE can then manually previous phase are referenced by the model and maintained refine the Model in order to group the information properly under configuration control. and create diagrams. Imported entities are linked to the documentation from which they has been extracted so that SE can quickly moves between model and documentation in order I. INTRODUCTION to look at detail not available in the model. SE can also Normally in the Space Sector, phase E is not managed and decides to update the model with additional information operated by the same team (customer/industry) responsible of included in the document that can be useful in the future. the previous phases. Currently the document centric approach is still the most used in previous phases so the possibility to inherit a model that can be used to manage operation phase is III. SENTINEL5P STUDY CASE quite low. However, the Operational Teams does not need to The first activity performed at the end of phase E1 (and before go in the system detail design but still can get benefit in terms of work effectiveness from the creation of a model that starting E2) by the Operational Team was to validate what has describes the keys aspect and refers the documentation been produced in the implementation stage versus the user baseline. The proposed approach has been used during the requirements. Using the methodology described in the Sentinel 5P transition from E1 to E2 phase and is currently previous section, the Operational Team SE imported used for the management of S5P Operation (Phase E2). system/user requirements and validation procedures. While Diagrams shown in this paper are examples extracted from the reading the procedure is “easy” to understand if a referred S5P Operation Model and have been generated using requirement has been tested as expected it is quite difficult to Enterprise Architect with Office MDG Integration. The check that all User Requirements are properly traced by approach refers to EA Suite but can easily adapted to a system requirements and by validation procedure. Typically, different tool providing the same functionality. The following documentation includes traceability matrix but the review of section describes the approach used, while last section shows the traceability performed just inspecting the document could an example of approach implementation. be time consuming and mistake can be missed (e.g. requirements or procedures missing in the traceability matrix II. APPROACH DESCRITION or referring removed entity). Using the approach described The main activities performed during the validation and above the SE, reducing the time for checking and guaranteeing operation phase are: that no error are missed, was able to detect:  Validation of the system versus user requirements;  6 user requirements not properly traced by system  Documentation Baseline Management; requirements (mainly typo in the traceability);  NCR and CR analysis.  About 40 system requirements not referring to any In order to manage effectively the above activities the SE user requirement; automatically extracts from the available documentation (e.g. User Requirement Document, System Requirement  About 20 procedures not referring to any system Document, Architectural Design Document, Master ICD requirement; Document, Validation and Verification Plan, etc) and imports  About 10 system requirements not traced by any in the model key information like: requirements, building procedure (mainly typo in the traceability). Sparx EA allows displaying a traceability matrix and link/reference generated in the model the risk to underestimate highlighting missing relation in both direction (see Fig. 1). impacts is heavily reduced. Fig. 1. EA Traceability Matrix Usually using document based approach the management of the documentation baseline is mainly done ingesting document in a repository/DMS allowing cataloging and configuration control, typos/errors in the management of a documentation tree are quite common. An MBSE approach allows to create a documentation tree in order to define dependences in documents and to proper assess any impact of a document update. Using the CIDL document entities are automatically created in the model and using applicable and reference table Fig. 3. NPP-Cloud Processing dependency and/or generalization link can be created (see Fig. 2). Fig. 2. Documentation Tree To analyze NCR and CR impact properly the Operational Fig. 4. Maintenance Diagram Team SE imported for related documentation additional entities like Interfaces, DataType and Process. These entities IV. CONCLUSION were linked to the documents entities in order to allow the SE to quickly identify using the model where the imported entity Thanks to the described approach, it was possible to create an is described in detail. During the operational phase, one of the operational model for S5P in less than three working weeks. main user of S5P data requested to have CH4 data within 2 Future improvement would be to create ad hoc template in days from sensing. So S5P Mission Manager requested an order to automatically generate a subset of the project analysis to SE. Browsing the model he identified a document (MICD, CIDL, TNs, …). dependency of the CH4 processing from Cloud NPP processing (L2_NP_*) and a dependency of Cloud NPP REFERENCES processing from the availability of VIIRS auxiliary data (Fig. [1] International Council on System Engineering,“Systems Engineering Handbook” INCOSE-TP-2003-002-04, 2015 3). After an analysis on the delivery policy of the VIIRS data [2] S. Friedenthal, J. Wolfrom, “Modeling with SysML”, presentation to the SE prepared a maintenance diagram where all the needed the INCOSE International Symposium 2010, Chicago. changes and impacted entities are identified (Fig. 4). Analysis [3] L. E. Hart, “Introduction to Model-Based”System Engineering and was completed in less than one day and thanks to SysML”, presentation at INCOSE Chapter Meeting, 2015