M´ etodos distribucionales

Now that we have identified the Business patterns in this scenario, we need to identify the high-level logical components of the solution and their interactions. This will allow us to choose an appropriate Application pattern.

On a larger or more complex systems, you would probably use systems analysis and design tools such as Entity Relationship and dataflow diagrams. Due to the simplicity of our system we do not need to do a lot of analysis in order to understand and map the existing systems or to design our new system.

Before selecting appropriate Application patterns, we first analyze the processes that are required in the new system.

6.3.1 Process analysis

Figure 6-3 New consolidated process flow

The following sections outline the process flows identified in the Figure 6-3. Step numbers in the diagram correspond with the steps identified in these sections.

Searching for a member from an Internet browser

The following steps describe the new process of searching for a member from an Internet browser:

1. A member of the public fills in a Web form at the JPA Web site, requesting the JPA’s membership directory be searched with one or more search conditions applied. 2. The Web site responds with the search results for the specified condition.

3. If the user wants to see the professional member’s detailed information, the user clicks the link of the professional member name on the result screen.

4. The detailed professional member information is displayed on the Web browser.

Applying an update to a JPA member’s home page

The following steps describe the new process of applying an update to a JPA member’s own home page:

5. The JPA member is able to update their individual home page and some of the information that is stored within the database after the system has verified the user ID and password with the membership security directory.

6. When the member record is updated, the updated information is stored in the membership database and the search index is updated.

Changing the members’ passwords

The following steps describe the new process of changing the members’ passwords in the membership security directory:

7. The member fills in a Web form requesting the password change with the user ID and

Member Public JPA member search function 1. Search request 2. Search result 3. Detail information request

4. Detailed information

5. Information update

7. Password update request

9. Passwords change confirmation

JPA member information update function Search results Detail information 8. Password update Identity confirmation Detai l infor matio n and i ndex upda te Membership security directory Membership information database Membership information index

8. The new password is stored in the membership security directory after verifying the user ID and current password.

9. A password change confirmation is posted to the member’s Web browser to confirm that the password change took effect.

6.3.2 Determining an appropriate Application pattern

Thus far, we have identified two Business patterns that apply to JPA Membership Services: Self-Service and Access Integration. Based on this analysis, and additional studies of published IBM Patterns for e-business, the “Account Access” composite pattern, which includes these two Business patterns, seems like an appropriate pattern to apply to this scenario. As described by Adams, et al., account access solutions provide customers with around-the-clock access to their account information (p. 71).

The Account Access composite pattern includes two mandatory pattern components: access integration and Self-Service. Both of these patterns apply directly to this scenario:

Access Integration

Provides for access to enterprise information through several devices, including regular browsers, PDAs, and mobile phones. JPA would like the public to be able to access JPA member information from a variety of devices.

More specifically, the “Pervasive Device Access” application pattern, described in IBM Patterns for e-business, facilitates the extension of an individual application from browsers to pervasive devices, including PDAs and mobile phones.

Self-Service

Provides access to information stored in core business systems and databases. In this scenario, JPA would like its members to be able to access their own account information at any time. Public users must also be provided with access to JPA member information. The “Stand-Alone Single Channel” application pattern, described in Patterns for e-business: A Strategy for Reuse by Jonathan Adams, et al., narrows the focus of the Self-Service pattern for situations that do not require a structure for integration to multiple back-end systems. The JPA Membership Services system does not include any

requirement to extend the reach of application data into other enterprise systems. Figure 6-4 represents the patterns involved in this scenario, in the context of the Account Access composite pattern.

Figure 6-4 Account Access composite pattern applied to the JPA Membership scenario

In our case, the pervasive device access pattern applies almost directly to the JPA scenario, as shown in Figure 6-5, and will thus be mapped to our Runtime topologies described later in this chapter.

Figure 6-5 Pervasive Device Access pattern

Account access solutions may consist of additional components that are not yet included as requirements for the JPA system. These components include:

The solution may optionally include an Information Aggregation pattern in cases where information from multiple accounts is summarized to provide a single unified portfolio view to the customer.

The solution can also include the Collaboration business pattern as functions such as online chat with a customer service representative and help desk support are added to it.

If the solution has any one of the optional Business patterns, the solution may optionally include an Application Integration pattern to seamlessly combine multiple Business patterns. Application Tier 1 Application Tier 2 Meta Data Read-Write Data Pervasive Device Access Tier Pervasive Device Client Tier