Zugl.: München, Techn. Univ., Diss., 2008 / Hergestellt on demand

Techn. University, Habil.-Schr., 2003--Berlin.

Techn. University, Diss., 2005--Berlin.

A system requirements specification (SyRS) defines a set of functionalities that a system is expected to fulfil. A requirement may be “it is always the case that actualFuelLevel is greater than or equal to 0” for an industrial system. Inconsistencies in a SyRS may require the system to be redesigned or reimplemented, which can drastically increase costs. With the increased size and complexity of SyRS it is important to assess new methods for verifying their correctness with respect to some criteria such as consistency. PROPAS is a tool for automated consistency checking of SyRS developed within the VeriSpec project, a cooperation between Mälardalen University, Scania and Volvo GTT. The tool is based on satisfiability modulo theories (SMT) techniques and operates on SyRS encoded in formal notation, that is timed computation tree logic (TCTL). In this thesis we extend the functionality of the PROPAS tool by implementing a type-inferencing mechanism such that variable types in SyRS can be automatically inferred. For validation, we apply the extended PROPAS tool on a set of industrial requirements. The results show that the type-inferencing mechanism can correctly infer the types of the variables from the set of requirements in most cases, while in the same time not introducing significant computational overhead to the existing solution.

yes / This paper presents a structured approach for systems requirements analysis that integrates use case modelling with a coherent flows based approach for describing interface exchanges based on the Interface Analysis Template. The approach is discussed in the context of current frameworks for requirements elicitation from the engineering design and systems engineering domains, and it is illustrated with an automotive case study. This illustrates the strength of the framework to support structured multi-domain and multi-disciplinary analysis of requirements for complex systems.

Zugl.: Bremen, Univ., Habil.-Schr., 2005

This thesis investigates how a web-hosted portal could be developed and designed in order to assist customer information updates in micro-enterprises in the ship broking business. Based on well-established system development theories and collected material, the web-hosted portal concept was developed. The development process included a case study at a ship broking company in Karlshamn, southern Sweden. Ship broking companies handle information as a mediator between other actors, thus the information becomes sensitive. In the ship broking business there is a constant need and flow of information. As the shipbrokers’ customers demand constant information 24 hours a day it is important to meet this demand in a service minded fashion. Today all customer updates are handled manually and are considered very time consuming and generate duplication of work. To solve these issues a possible solution could be to introduce information technology in the organisation. The introduction of information technology in the ship broking organisations has been slow. A contributing factor might be the widespread conservatism and resistance to changes in the ship broking business. The conclusions show the needs and demands for a web-hosted portal among shipbrokers and interested parties in the logistic chain. The result of the thesis should be considered as a foundation for further development and implementation of the concept.

The thesis focuses on requirements, which must be established when business intelligence is chosen, from user point of view. Business intelligence je decision support system and it is very important, that system must be ease of use and provide expected information for analyst and managers. During the process of choosing the software, they are the one, who provide requirements and expectation of the system. The thesis focuses on mapping those requirements and their importance using survey among analyst and managers, who uses business intelligence or want to use it.

Driven by the gradually increasing electrification of the transportation industry, in particular the aviation sector, the future’s electrified aircraft requires not only an improvement of the flight operation, but also an enhancement of the movement on ground. One very promising concept to improve the taxiing operation is the integration of an electric propulsion system into the aircraft’s undercarriage, also called “Electric Taxiing”. This yields a decrease of the overall fuel consumption, reduction of emissions, and improvement of aircraft maneuverability to help reducing operating times on ground. In this thesis, the performance requirements for an electric taxiing system are investigated by using self-recorded real-life aircraft taxiing drive cycle data. Based upon the system requirements, the powertrain for the electric propulsion system is sized for a commercial midsize aircraft to achieve a similar driving performance to conventional taxiing maneuvers. The sized powertrain, including the determined electric motor characteristics, is evaluated using a developed simulation model which allows testing the proposed electric taxiing system given the attained drive cycles. For the electric machine which is implemented into the wheel of the aircraft’s main landing gear, an axial flux permanent magnet (AFPM) motor with segmented stator windings is selected due to its very compact structure while providing high torque capabilities. The AFPM motor is designed and evaluated by using analytical models and three-dimensional finite element analysis (3D FEA) to fulfill the specified motor characteristics required for the electric propulsion unit. Finally, suggestions for potential improvements and future work are discussed. / Thesis / Master of Applied Science (MASc)

The basic objective in bulk electrical system planning is to determine the necessary generating facilities required to ensure an adequate and economic supply of electrical energy and the development of an adequate transmission network to transport the generated energy to the customers. Quantitative adequacy assessment is a basic task in achieving this objective. An important requirement in this task is the ability to forecast the system load requirements at specific times in the future. These forecasts must also recognize the inherent uncertainty in predicting the future load demands.<p> The primary focus of the research described in this thesis is to examine the effects and implications of load forecast uncertainty on the load point and system adequacy indices of a composite generation and transmission system. This thesis considers two techniques to incorporate the inherent uncertainty associated with future load forecasts in the adequacy assessment of bulk electrical systems. Base case and factor analyses are performed on a number of power system configurations to identify and address the relative contributions to the load point and system indices due to load forecast uncertainty. A transmission reinforcement option and a number of generation system expansion options are presented to examine the system reliability response due to load forecast uncertainty.<p> The actual magnitudes of the changes due to load forecast uncertainty in the load bus and system risk indices and in the percentage change values are different for each generation expansion scenario. The topology and parameters of the system are different in each of the studied power system configurations. The effect of load forecast uncertainty on the system and load point adequacy can be quantified and utilized in the decision-making process associated with system generation and transmission planning. Load forecast uncertainty has important impacts on the system and load point indices that can only be appreciated by conducting comprehensive bulk system adequacy assessment. The actual effects are a complicated function of the system topology and parameters, and the system load curtailment philosophy.