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Efficient design-time management and documentation of run-time data elements are of paramount importance when developing and maintaining modern real-time systems. In this paper, we present the results of an industrial case-study in which we have studied the state of practice in data management and documentation. Representatives from five companies within various business segments have been interviewed and our results show that various aspects of current data management and documentation are problematic and not yet mature. Results show that companies today have a fairly good management of distributed signals, while internal ECU signals and states are, in many cases, not managed at all. This lack of internal data management results in costly development and maintenance and is often entirely dependent of the know-how of single individual experts.

Furthermore, it has, in several cases, resulted in unused and excessive data in the systems due to the fact that

whether or not a data is used is unknown.

In this paper the data-entity approach for efficientdesign-time management of run-time data in componentbasedreal-time embedded systems is presented. The approachformalizes the concept of a data entity which enabledesign-time modeling, management, documentationand analysis of run-time data items. Previous studies ondata management for embedded real-time systems showthat current data management techniques are not adequate,and therefore impose unnecessary costs and quality problemsduring system development. It is our conclusion thatdata management needs to be incorporated as an integralpart of the development of the entire system architecture.Therefore, we propose an approach where run-time datais acknowledged as first class objects during developmentwith proper documentation and where properties such asusage, validity and dependency can be modeled. In thisway we can increase the knowledge and understanding ofthe system. The approach also allows analysis of data dependencies,type matching, and redundancy early in the developmentphase as well as in existing systems.

This thesis presents new techniques for data management of run-time dataobjects in component-based embedded real-time systems. These techniquesenable data to be modeled, analyzed and structured to achieve proper datamanagement during development, maintenance  and execution.The evolution of real-time embedded systems has resulted in an increasedsystem complexity beyond what was thought possible just a few years ago.Over the years, new techniques and tools have been developed to managesoftware and communication complexity. However, as this thesis show, currenttechniques and tools for data management are not sufficient. Today,development of real-time embedded systems focuses on the function aspects ofthe system, in most cases disregarding data management.The lack of proper design-time data management often results in ineffectivedocumentation routines and poor overall system knowledge. Contemporarytechniques to manage run-time data do not satisfy demands on flexibility,maintainability and extensibility. Based on an industrial case-study thatidentifies a number of problems within current data management techniques,both during design-time and  run-time, it is clear that data managementneeds to be incorporated as an integral part of the development of theentire system architecture.As a remedy to the identified problems, we propose a design-time data entityapproach, where the importance of data in the system is elevated to beincluded in the entire design phase with proper documentation, properties,dependencies and analysis methods to increase the overall system knowledge.Furthermore, to efficiently manage data during run-time, we introducedatabase proxies to enable the fusion between two existing techniques;Component Based Software Engineering (CBSE) and Real-Time DatabaseManagement Systems (RTDBMS). A database proxy allows components to bedecoupled from the underlying data management strategy without violating thecomponent encapsulation and communication interface.