Firstly, an improved descriptive method based on OWE (object With Event) for software component has been analyzed and discussed. Then, the strategy for the implementation of software reuse is probed into. At last, the...
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Firstly, an improved descriptive method based on OWE (object With Event) for software component has been analyzed and discussed. Then, the strategy for the implementation of software reuse is probed into. At last, the support of Inheritance mechanism for software reuse and an improved strategy in distributed processing environment have been stressed on.
Industrial practices in Requirements Engineering do not give the right place to formal methods. Two main reasons explain why such a failure arises. First of all formal methods have not promoted a dedicated SLC (Softwa...
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ISBN:
(纸本)0818685859
Industrial practices in Requirements Engineering do not give the right place to formal methods. Two main reasons explain why such a failure arises. First of all formal methods have not promoted a dedicated SLC (Software Life Cycle) which should have been easily integrated within the upper phases of the traditional V-like or Waterfall-like model. A second reason is that formal methods have failed in scaling zip. In this paper we show how the requirements elicitation phase can take advantage of formal methods. We report the industrial and successful experience [2] undertaken by the STNA(1), a governmental office responsible for the French ATM (Air Traffic Management) system. We exhibit the evolutionary model which was applied to develop both a validated object-oriented model of a particular ATM subsystem, and a formal specification of some of its safety critical parts. We then show that the SRD (Software Requirements Document) is the key of the whole development. Its writing requires a strongly related cooperation of two different teams that are effective actors of the evolutionary model. We conclude the paper in exhibiting some recommendations.
摘要摘要自動化製造系統(automated manufacturing system / AMS)常會面臨資源衝突(conflict)與死锁(deadlock)情形的發生，如何充分掌握系統動態行爲的特性、事先的偵測與排除死鋇情形，並獲得一良好的作業排程，將直接且迅速的影饗AM...
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摘要摘要自動化製造系統(automated manufacturing system / AMS)常會面臨資源衝突(conflict)與死锁(deadlock)情形的發生，如何充分掌握系統動態行爲的特性、事先的偵測與排除死鋇情形，並獲得一良好的作業排程，將直接且迅速的影饗AMS之生產縝效，也成爲發展AMS的成敗關鍵。本研究以彩色時間性物件導向裴氏画(colorcd timed object-oricntcd petri net/CTOPN)爲基礎，發展出CTOPN排程演算法，針對經由CTOPN抆式分析及驗證過控制邏輯的AMS進行排程分析，並迅速的獲得一近似製距時問(makespan)最短的現圾排程。CTOPN模式不但具備裴氏圇(petri net)圖形化表逹及控制邏輯數理分析能力，擁有物件導向髙模組化、重複使用和易於維護更新等特性，並同時提供一整合的技術與環境，有效的將建模(modeling)、分析、排程與控制整合於AMS系統的發展與與建構過程中。AbstractResource conflicts and deadlock are two critical problems in an automated manufacturing system (AMS), the successfulness of an AMS is highly depending on if we can coordinate the dynamic behavior in an efficient and effective manner (e.g., detect and avoid deadlock, follow an efficient operations schedule). In this paper, a new paradigm, called CTOPN (colored timed object-oriented Petri net), is employed to model the dynamic behavior of an AMS, then a scheduling algorithm is developed to search et near optimal operations schedule for the AMS modeled by a CTOPN in terms of minimum inakespau. The CTOPN approach owns not only the characteristics of Petri nets (e,g., graphical representation and mathematical analysis capability of the control logic) and object-oriented approach (e.g., the high degree of modularity, flexibility, reusability, maintenanability of the model), but also provides an integrated and consistent environment for modeling, analyzing, scheduling and controlling an ANTS simultaneously.
An integration of formal syntactic constructs and object-oriented (OO) structural features is essential to a formalised OO method. It requires the formal semantics to be structured according to OO conventions. It also...
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ISBN:
(纸本)3540631143
An integration of formal syntactic constructs and object-oriented (OO) structural features is essential to a formalised OO method. It requires the formal semantics to be structured according to OO conventions. It also requires the OO features to be completely and consistently interpreted by format semantics. In this paper, a list of guidelines for achieving the integration is suggested. These guidelines are derived from a review of the existing formalised OO methods under two categories, OO style formal methods and formal style OO methods. The former possess a strong syntactic foundation but lack a complete coverage of OO features. The latter support all OO features but suffer from incomplete or inconsistent semantics. It is suggested that multiple schemas, on a common syntactic foundation with abstracted syntactic constructs that follow OO conventions, should be adopted.
The use of formal methods promises correctness, verifiability, robustness and reliability of operational software systems which have been developed so far. object-oriented methods enable easier development and mainten...
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The use of formal methods promises correctness, verifiability, robustness and reliability of operational software systems which have been developed so far. object-oriented methods enable easier development and maintenance of software application systems and promote the reuse of design and program code. Mapping formal specifications into an object-oriented application will therefore give a system that is not only correct and reliable, but easy to develop and enhance. In this paper, we show how specifications containing major decisions that financial managers typically make, can be expressed in the Z notation. These specifications are subsequently translated into pseudo object-oriented programs.
In this paper, a series of design methods for relational databases based on generalization and aggregation sematics is set up. The relationship between a class and its subclass is considered as a scheme constraint. Th...
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In this paper, a series of design methods for relational databases based on generalization and aggregation sematics is set up. The relationship between a class and its subclass is considered as a scheme constraint. The concept of inheritance dependencies, which describes the multiple inheritance among schemes,is presented in the paper. It is shown that the inference rules for inheritance dependencies are sound and complete. Furthermore, a series of results about the closure of inheritance dependencies and the minimal set of inheritance dependencies, which are analogues to functional dependencies, is obtained. In order to describe the aggregation semalltics, the concept of aggregation dependencies is given. It is easy to implement these constraints under relational database management systems.
This paper presents an object-oriented Petri net cell control (OPNCC) model for scheduling and controlling the operations of a flexible manufacturing cell. The development of the OPNCC model includes three phases: 1. ...
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This paper presents an object-oriented Petri net cell control (OPNCC) model for scheduling and controlling the operations of a flexible manufacturing cell. The development of the OPNCC model includes three phases: 1. Static analysis. 2. Dynamic analysis. 3. Integration. The dynamic analysis, the most important phase in developing the OPNCC model, will first construct the object-oriented Petri net (OPN) for each physical object and connect all the related ''encapsulated'' OPNs to be a complete OPN model to represent the dynamic behaviour or control logic of shop floor operations. Then, the control logic of the complete OPN model must be analysed through an object behaviour analysis, an inter-object message passing analysis and a conflict analysis. The OPNCC model not only possesses the characteristics of object-oriented method (e.g. inheritance, encapsulation and a higher degree of flexibility and reusability) and Petri nets (e.g. graphical representation and mathematical analysis capabilities), but also incorporates scheduling/dispatching knowledge in the control logic specified by the OPN model. The practical significance of the OPNCC model is that practitioners may apply it to develop both a real-time cell controller and an off-line shop floor scheduling simulator.
This paper presents an object-oriented Petri Net (OPN) approach to model and analyse the dynamic behaviours of an Automated Manufacturing System (AMS). Both the basic and the complete OPN models are introduced to repr...
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This paper presents an object-oriented Petri Net (OPN) approach to model and analyse the dynamic behaviours of an Automated Manufacturing System (AMS). Both the basic and the complete OPN models are introduced to represent the generic and specific dynamic behaviours of an AMS, respectively. Based on the basic OPN model, we need to construct the object Communication Net (OCNet) for each physical object, and then employ the theory of invariants to perform the deadlock analysis. For an analysed non-deadlock basic OPN model, the complete OPN model for a specific AMS may be effectively derived from it by only including those related system constraints (e.g. part routing, resource capacity), since the basic OPN class library is reusable. A conflict analysis approach is then introduced to identify all the conflicting events involved in the complete OPN model, so that the most suitable control/decision strategy for resolving each conflict event may be suggested. Consequently, a rule-based control software may be implemented directly from the specification of the validated complete OPN model by following a number of transformation rules. Copyright (C) 1996 Published by Elsevier Science Ltd
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