嵌入式即時系統的開發是一件十分複雜的工作，不僅要面對與設計一般系統相同的問題如使用者需求難以掌握等等，還必須克服即時系統所面對的時間限制問題。要解決這些問題，快速地開發出新的系統，並降低開發的成本，一個很重要的捷徑就是使用重用技術。本文中我們使用物件導向的重用技術，針對嵌入式即時系統的開發，提出一個框架(framework)的構想；框架是一個可重用之設計，包括一組類別(class)集合及其之間的互動關係。框架可由其互動關係及靜態結構兩個層面來展現。就互動關係之觀點，可將視框架為由五個元件(component)之組合，這些元件各司其不同之功能，由這些元件共同合作，以幫助設計者有效地開發嵌入式即時系統。構成框架的五個元件如下，分別是分析器(Analyzer)，任務器(Task Composer)，排程器(Scheduler)，作業系統管理器(OS Manager)及程式產生器(Code Generator)。就靜態結構來看，可將構成框架之所有基礎類別歸納成三個包裹(package)，表達嵌入式即時系統之抽象結構，其名稱如下，應用包裏(UsrApp)、即時作業包裏(RTService)及作業系統包裏(OSWrap)。設計者藉由繼承基礎類別之結構及關係，衍生適當之子類別，以符合應用之需求，而基礎類別間己定義完善之互動關係，將使實體化自子類別之物件，其互動關係有穩健之基礎。使用框架來開發嵌入式即時系統，不僅降低開發時間，縮短系統開發流程，更可提高產品品質，減少維護費用，讓產品更具競爭力。

The development of an embedded real-time system is a complicated task. Not only facing the same difficulty in general purpose system but also the stringent timing constraints on critical tasks. Using Reusing technique for system development is a shortcut. In this paper, a framework-oriented approach is presented to help efficiently design embedded real-time systems. The approach is based on an object-oriented framework, which is a reusable design expressed as a set of abstract classes and the way their instances collaborate. We presented our framework construct in two levels: collaboration and structures. At the collaboration level, the framework consists of five components, namely Analyzer, Task Composer, Scheduler, OS Manager and Code Generator. At the structure level, the framework is divided into three packages: UsrApp, RTService and OSWrap. The designer inherited the framework to customize their application. The structures of application objects derived from the subclasses inherited from the superclasses in the framework were well-defined. The robust relationships between application objects inherit of the relationships between superclasses in the framework. Using framework in embedded real-time system development can shorten the product development cycle and reduce the cost of maintenance thereby reduce the time-to-market of products.

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