Object-oriented methods (Computer science)

Frameworks for the development of object-oriented, user interactive applications have been examined. Three alternate approaches have been explored; the Model-View-Controller (MVC) approach, the MVC++ approach and the Presentation-Abstraction-Control (PAC) approach. For the purpose of assessing the approaches, a simple engineering application was selected for object-oriented analysis using the three techniques. The utility of each technique was compared on the basis of complexity, extensibility and reusability. While the approaches aim to provide reusable user interface components and extensibility through incorporation of an additional class, only MVC++ and PAC truly achieve this goal, although at the expense of introducing additional messaging complexity. It was also noted that, in general, decoupling of the GUI classes, while providing increased extensibility and reusability, increases the inter-object messaging requirement.

The Material Requirement Planning System (MRP) is a key module in the Enterprise Resources Planning (ERP) systems. Finding better ways of developing systems leads to a robust MRP system and provides prototypes which can be expanded to other modules of the ERP systems. This thesis will provide an object-oriented model of a MRP system which was created and presented by using the Object Modeling Technique (OMT). The model consisted of three parts, the object model, dynamic model, and functional model. An innovative way to handle the static bill of materials (BOM) data with a more flexible dynamic item class was developed. To demonstrate the flexibility, extendability, and reusability of the object-oriented MRP model, two major business change scenarios were applied to the model. Minor changes to the design were required to accommodate major changes on the functionality of the MRP system.

Current computer technologies and demands bring new challenges to the software engineering tools. This thesis includes a survey of software engineering environments, standards and technologies. It also examines the features needed to support rigorous object-oriented software development. The main contributions of the thesis are descriptions of innovative concepts and a high-level framework for a next-generation object-oriented software system development, management and maintenance environment, called IconSEE++, an Icon-based Software Engineering Environment.

Presented here is an object-oriented design for a real-time system used to monitor bus activity on a microcontroller via a PC. This system could prove to be an inexpensive and user-friendly alternative to existing hardware used for this purpose. The use of an object-oriented design methodology and the application of two Model-View-Controller architectures as well as a layered approach aided in producing a system composed of reusable components that is flexible and easily extensible. Additionally, a reusable pattern can be extracted from the architecture presented here that could be utilized in designing similar software applications for communicating with peripheral hardware devices.

Most popular object-oriented modeling techniques (OOMTs) provide good support for the creation of conceptual models of system behavior and structure. A serious drawback of these techniques is that the concepts and notations used are not rigorously defined. This can lead to the creation of ambiguous models, and to disagreements over the proper use and interpretation of modeling constructs. An important modeling construct that is often loosely defined is aggregation. This thesis presents a precise characterization of aggregation that can help developers identify appropriate applications of the concept. Our characterization is the result of careful analysis of literature on conceptual modeling, knowledge representation and object-oriented (OO) modeling. We discuss primary and secondary properties of aggregation and propose annotations for UML (Unified Modeling Language). An extensive discussion of the more useful patterns of aggregation helps developers pick a suitable prescription of aggregation.

The rich structuring mechanisms, and abstract modeling constructs available in most graphical object-oriented modeling methods (OOMs) facilitate the creation of abstract, visually-appealing, highly-structured graphical models. On the other hand, lack of formal semantics for the modeling notation can severely limit the utility of OOMs. Formal specification techniques (FSTs) support the creation of precise and analyzable specifications, but they can be tedious to create and difficult to read, especially by system developers not trained in formal methods. The complementary strengths of OOMs and FSTs suggest that their integration can result in techniques that can be used to create precise and analyzable models. This thesis describes a technique for integrating analysis level UML (Unified Modeling Language) Class Diagrams with the formal notation Object-Z.

Current object-oriented development methodologies do not introduce distributed system architectural aspects early enough in the system development cycle. A development partitioning scheme that includes the system level, in addition to the problem and application levels, will encourage analysis that includes elicitation of non-functional system requirements. These requirements include response time with respect to system communication load, fault tolerance, safety, security, and real-time deadlines, among others. They can be documented with an extended form of Jacobson's use cases. Where use cases describe how a system will work from a user's point of view, extended use cases add the capability to describe how well it should work. System level analysis information can be graphically depicted on extended forms of Unified Modeling Language (UML) interaction diagrams and on multilevel architecture diagrams.

Many methodologies for software modeling and design include some form of static and dynamic modeling to describe the structural and behavioral views respectively. Modeling and design of complex real-time software systems requires notations for describing concurrency, asynchronous event handling, communication between independent machines, timing properties, and accessing real time. Function-oriented structured analysis methodologies such as Ward and Mellor's SA/RT and Harel's Statecharts have provided extensions for real-time system modeling. Dynamic modeling of real time systems using object-oriented methodologies also requires extensions to the traditional state machine notations in order to convey the real time system characteristics and constraints. Shaw's Communicating Real Time State Machines (CRSM's), Harel's O-Chart notations, and the Octopus methodology provide methods for modeling real-time systems consistent with object-oriented methods. This thesis proposes an object-oriented analysis and design methodology that augments the traditional Object Modeling Technique (OMT) dynamic model with real-time extensions based on high-level parallel machines and communication notations from CRSM. An example of the proposed methodology is provided using a realistic but hypothetical example of an automated passenger train system. A design refinement step is included for fault tolerant considerations. An evaluation of the proposed methodology with its extended notations is provided.

The inventory is a key element in modern manufacturing systems. We present here object-oriented manufacturing inventory models, including detailed static and dynamic models. Three different representations of the object model are presented and compared. Two case studies are given to verify the extensibility and reusability of the models. One of the models is developed into a pattern, that can be used as a prototype for similar type of systems, e.g., an inventory of the books in a library. Comparison of our inventory model with other inventory data models is also presented.

Use cases and scenarios are used by most of the object-oriented modeling approaches for capturing users' requirements, analyzing the system and building the test cases. All the different methodologies have different approaches for modeling use cases and applying them to other object-oriented models. Use case models help the analyst to construct dynamic as well as static models. In this thesis, we show an approach of modeling use cases for object-oriented software analysis. We give emphasis to modeling the sequences of the activities within the scenarios and the sequences of the scenarios throughout the system. We show how these sequences influence the static model (object diagram) and dynamic model (state diagram). We propose an Integrated State diagram for dynamic modeling and an Object Interaction diagram for modeling the flows of the scenarios throughout the system by applying the use case sequence models. Our approaches are demonstrated by solving a variety of examples.