First, this paper analyzes the basic difference between knowledge-base firm and non-konwledge-based firm;second, it is concluded that the command-and-control model can t applied to the knowledge-based firm based on the analysis of the management requirements of knowledge-based firm.

The paper introduces the method of realizing undo/redo in CAD software development by using command pattern and analyzes in detail the process of its implementation and some problems that need paying attention to.

A command pattern oriented distributed system is proposed.

UML Command Mode Based Audio Player System;

The concept of command manager is brought forward and command caller is used to separate the command processing strategy from command class,so it may make the logic of com-mand implementation simple.