在概要設計時，發現參與討論的人對什么是模塊,模塊的劃分根據是什么的認識有很大的差異。
我也不敢亂下定論，還是看看書本是怎么說的：
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1 .參考一下《軟件架構藝術》一書，Stephen T. Albin  在里面描述：

Modules are discrete units of software (binary and source). Binary modules are instantiated at run time and these instantiations are commonly called components and connectors. A given module may contain the specifications for several component types and connector types. The component (instances) may be of a fixed number in some situations. For example, a Web server executable, when launched, results in a single Web server component instance. The Web server module is the binary code that exists as a set of program files. The Web server component is a running instance of the Web server.

I have seen some confusion over the use of the terms module, component, and connector. A module is a discrete unit of design that is composed of a hidden set of elements and a set of shared elements. Modules have high internal cohesion and low external coupling. Modules may represent the physical packaging of the application's binary code, which can be described further by component types and connector types. Components and connectors describe the physical instantiation of a system. The term component is often used to mean a component type or module. A module refers to a unit of software that can be designed, implemented, and compiled into a deliverable executable system or subsystem; it is a unit of execution. A component is a runtime entity, the definition of which exists in a module. A classic modular architecture is a client-server system. The client and the server are two modules. The server exports some elements such as a set of publicly visible relational database tables and views. The client knows about this publicly visible schema. The client and server are unaware of the internal composition of the other.

那么按紅色部分來說，如果說一個dll或一個Exe里由多少個模塊組成這將是的笑話了。
2 .參考Mary shaw的《軟件體系結》：
    模塊式軟件被劃分成獨立命名的，并可被獨立訪問的成分。模塊劃分，粒度可大可小。劃分依據是對應用邏輯結構的理解。
這個定義，似乎有沒有《軟件架構藝術》那么嚴格。沒有定義具體什么為“被獨立訪問”的成分。
3. 《Documenting_Software_Architectures》
   A module tends to refer first and foremost to a design-time entity. Parnas's foundational work in module design (1972) used information hiding as the criterion for allocating responsibility to a module. Information that was likely to change over the lifetime of a system, such as the choice of data structures or algorithms, was assigned to a module, which had an interface through which its facilities were accessed.
    其說，模塊是設計時的實體，特點是信息隱藏和能通過模塊的接口訪問。在介紹模塊視圖時他說：
    A module is a code unit that implements a set of responsibilities. A module can be a class, a collection of classes, a layer, or any decomposition of the code unit. Every module has a collection of properties assigned to it. These properties are intended to express the important information associated with the module, as well as constraints on the module. Sample properties are responsibilities, visibility information, and author. Modules have relations to one another. Example relations are is part of or inherits from.
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不同的作者有不同的看法，但綜合一下，我認為模塊因該是一個獨立設計的單元，并為其他模塊提供訪問接口。也就是說，他是一個架構中的設計元素，但不限制他的存在模式，也就是他是提供了可訪問接口而且實現某一功能的一個實體，可以是一個類或一組類或可執行程序等。