Workflow Applications Architecture for Exchange Server

A workflow application consists of forms and documents that a user manipulates and tools on the server that manage those documents according to a set of rules. The application architecture is comprised of a presentation layer and a business logic layer.

Presentation Layer

A workflow application includes forms or documents with which the user interacts directly. This layer is called the front-end layer, or presentation logic, of the application. It could be a Microsoft® Word document, a Microsoft® Outlook® form, or some other presentation layer that you design. These all work, because workflows are triggered by any save or post in the workflow folder, and the Microsoft® Exchange 2000 Server Web Store provides heterogeneous document storage. Whatever you use as your presentation layer is up to you and has no relation to the functionality addressed by CDO Workflow objects. This layer is independent of CDO Workflow objects and usually runs on a client computer.

Business Logic Layer

You use CDO Workflow Objects to design and run workflow applications. These applications contain the business rules that govern your document approval and routing processes. While the presentation layer usually runs on a separate client computer, the business rules run on the server with the Web Store, where the target documents are stored. Your business logic or workflow layer operates in a separate process from the Web Store process. You can create the workflow process using any language, such as Microsoft® Visual Basic®, and create event sinks, or you can use the Workflow Designer for Exchange 2000 Server in the Microsoft development environment.

In This Section

• Workflow Applications
  Workflow processes are used to enforce business rules, such as who sees an item, the sequence of events an item goes through, the routing of an item, or even when an item can be created or deleted.
• Exchange Server and Public Folders
  Behind the scenes, the Workflow Designer uses Collaboration Data Objects (CDO) Workflow Objects for Exchange. CDO is a set of COM components that integrates seamlessly with the Microsoft® ActiveX® Data Objects (ADO) 2.5 component.
• Application User Interface
  An important task in developing any application is designing the user interface.
• Workflow Scripting
  The built-in functionality of workflow events can be enhanced using Microsoft® Visual Basic® Scripting Edition (VBScript).

Related Sections

• Developing Workflow Applications for Exchange Server
  Generally, the term "workflow" is used to describe applications that are modeled as business processes. Typical workflow applications include forms routing/approval, document review/publishing, and issue tracking.
• Planning a Workflow Process for Exchange Server
  As with all development, planning is the key to creating successful applications. The Workflow Designer for Exchange 2000 Server automates many of the activities required to create a workflow process for Exchange.
• Building a Workflow Process for Exchange Server
  The Workflow Designer for Exchange 2000 Server makes it possible for you to build, modify, and add script to workflow processes for Exchange folders or SharePoint Portal Server folders.
• Developing the User Interface for Exchange Workflow
  Typically, the user interface is independent of CDO Workflow objects and runs on a client computer.
• Scripting in the Workflow Designer for Exchange Server
  Add functionality to your workflow process by using Microsoft® Visual Basic® Scripting Edition (VBScript).
• Advanced Workflow Process Management
  When you have created your workflow processes using the Workflow Designer for Exchange 2000 Server, you can use the advanced management features.
• Troubleshooting Workflow Applications for Exchange Server
  This topic provides information to help you avoid or resolve the most common errors and issues you might encounter when using the Workflow Designer for Exchange Server.