This solution avoids the need for integration code to be built. It can be used internally within the enterprise to establish a federated portal environment. There is no reason why the companies own Web applications should not be WSRP enabled also to add greater deployment flexibility in the future.

Applicability

• Consumption of an existing Web application where a producer can still manage presentation but also offer its functionality via a Web service (Web services used to be predominantly for business/data exchange)
• Custom produced for long-term legacy Web application where it can remain in its existing infrastructure and be reused elsewhere (federation)

Known Uses
WSRP is supported by many leading portal vendors, including BEA, Microsoft, Oracle, TIBCO, and IBM.

3.  Composite Portal Application
Problem
We may wish to build new applications that extend existing COTS-based systems, but changing them will cause maintenance and upgrade issues. Also the processes involved in a new application may involve many existing systems, and therefore building the solution in any one system will cause tight coupling between the systems.

Solution
A company's operations can be described by a finite set of business processes and data elements. These business process and data elements are implemented in IT systems. The wrapping up of these into "services" that can be easily reused is one of the fundamental tenets of service-oriented Architecture (SOA).

Most SOA strategies include an orchestration capability that allows the composition of a set of shared business services to form an application or new business process. Because of the open nature of Web services these process and business services can be easily accessed from anywhere, including the Web presentation tier, which is termed a composite portal application. The composite application is left only to deal with the presentation aspects of the application.

Applicability

• Preferred when an SOA strategy is in place, in particular to provide a unified front end and to help establish more coverage within service catalog
• Creating Web enablements of EIS tier reusing EAI services
• To extend a systems capability while maintaining its vanilla implementation
• Building applications that span multiple systems and resources
• Providing the greatest business agility once there is a well established and populated service registry
• Building macro-level workflow capabilities across the enterprise

Known Uses
There is a huge market for SOA related products. Business Process Execution Language (BPEL) is a stabilizing and prominent second generation web service technology that provides Orchestration capabilities. BPEL compliant platforms are available from many vendors - Microsoft BizTalk, BEA AquaLogic & WLI, IBM WebSphere to name only a few.

4.  Web Clipped Portlet
Problem
An existing application may already functionally match your requirements but it is outside of your control: maybe it is provided by an external party, maybe the development team have moved on, and it probably does not strategically match both architecturally and in terms of corporate look and feel.

Solution
Web clipping acts as an intermediary that allows the user to interact with ANY Web application, extract and manipulate its content, and finally present it in a portlet conforming to your branding and style guide. The solution will likely still require investment in an SSO interface.

Web clipping has become quite sophisticated in recent years. Vendors such as Kapow not only offer clipping of all types of Web content (including JavaScript), but also the harvesting of data into a virtual data model, and now more recently the wrapping of Web access behind a more ideally modeled Web services interface. This provides a lot of flexibility in helping to extend the reach of the SOA.

Of course the main issue with clipping another party's content is stability when the content changes. This needs to be addressed upfront in the design both technically and operationally.

Applicability

• When you cannot influence the design of a strategic/longer-term application
• To harvest tactical Web applications with little to no involvement from the development community
• When the Web application comes from a third-party supplier and is unchangeable
• When the layout or style of a Web application would prohibit a direct encapsulation pattern

Known Uses
Kapow offers both stand-alone products and is also integrated into BEA WebLogic Workshop.

5.  Direct Content Encapsulation
Problem
A Web application is already available and deployed that offers the required functionality, but is not viewed within the strategic portal environment.

Solution
Create an appropriately sized portlet to host the display of an external Web applications content as-is. You need to employ the use of an HTTP proxy in the portal framework so that it can essentially act as a client to the external Web application and handle cookies if necessary. Still usually requires investment in an SSO interface.

Applicability

• This is a cheap option for integration if content is already laid out and branded appropriately. Control of format and look and feel is very limited, unlike the Web clipping option.

Known Uses
Most portal vendor platforms provide the ability to easily encapsulate content into a portlet view.

6.  Separate Browser Launch
Problem
A legacy Web application already exists and the user community or business is unwilling or unable to migrate to a new strategic portal.

Solution
Provide a simple option to maintain a URL link to a separate Web server and launch the application in a separate browser window. Still usually requires investment in an SSO interface.

The strategic portal environment at least gets to act as an SSO launch pad for all applications and centralizes authorization (to see links).

Applicability

• When the web application is non-strategic or little investment needs to be made in its integration into portal
• When content size/layout precludes inclusion in a portlet
• The business is unwilling/unable to move to a more preferred architectural solution
• The portal environments must be seen to become more unified rapidly

Known Uses
Separate Browser Launch is probably the easiest and cheapest form of Web integration (when a legacy Web app already exists).

An Order of Preference?
It is useful to not only present the choices such as those above but to also let your organization know what the architectural preference would be given all things being equal.

The benefits matrix in Table 1 helps to illustrate when one approach may be more appropriate than another. Given this information, we can establish an order of preference.

We can see that the earlier misguided (or incomplete) requirement "provide single sign-on to <legacy> application" with no other architectural considerations applied, e.g., option #6, represents the least preferred solution from an architectural perspective.

Summary
Eradicating Web sprawl within an organization often feels like a never-ending task. One way to help is to undertake the classification of the context of candidate solutions to Web enablement, to catalog them in a simple fashion, to establish an architectural order of preference, to present and publish the approaches, and to make their use part of the delivery processes within your organization. Within time the correct solution context will be selected further upstream in the requirements process and the evolution to the target architecture will accelerate.