近年來，因為資訊科技的進步與發展，使得人與人之間的距離越來越近，
企業與企業 之間的交流也因為電子商務而日益頻繁。電子商務的範圍非
常廣泛，上至企業間的電子文 件交流，下至企業內的電子文書作業與會
計帳務，無一不囊括其中。
不管是企業間或企業內的流程都有一個共通點，就是電子文件的傳遞不比
實際文書的 傳遞那樣的容易認證。所以如果有人否認曾經在網路上下訂
單，或是傳遞商品資訊，又或 是在企業內的會計系統做假則後果將不堪
設想。
所以將一企業流程劃分為若干子流程後，其各子流程，應該負起認證的責
任，以及在 給定的資源下，盡其所能完成交付之任務，所以本文結合代
理人的觀念與企業子流程應有 的“任務”、“認證”、“權限”與“功
能”，提出信託人（attorney）概念，並且依照 企業運作模式，以裴氏
網路（petri net）與document-centric為基礎，提出信託人資源 協調
網路（attorney resource coordination net）模式，來模式化企業程序
。 最後並以此模式應用於電子商務之商品資訊傳遞與購物流程，以及第
一菸酒公司之會 計與帳務系統。

As information technology develops and progresses, electronic
commerce (EC) play a very important role in people''s
daily lives and business processes. The interchange of
electronic document and the accounting systems of business are
both important elements of electronic commerce. Although EC has
become more and more popular in business, there are
serious problems to be solved. The most important of all is
the security issue. Because the transformation between
electronic documents can not be authenticated as easily as that
between physical paper documents, the security of network usage
is doubtful to users for a long time.
Therefore, this paper provides a model to solve the mentioned
problem above. Our ARC/EC model extends the petri net, and
combines the concept of "agent" in order to model the EC
business system. To emphasize the responsibility of being
authenticated, we use "attorney" to state the process of
business instead of "agent". Every attorney of our model
includes four elements, namely "mission", "authentication",
"rights" and "functions", with which the attorney can perform
tasks, and all the transformation processes will then be
recorded for later on auditing. These records provide
important information to audit every process the attorney did,
so the security of network usage can be trusted.
At last, we apply this model to case studies and show how ARC
net model can be use to model electronic commerce and
accounting finance information systems.