Step 4

Step 4 is to select the services portfolio required per building block.

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Objective

The objective of this step is to select services portfolios for each building block generated in Step 3.

Approach

The services portfolios are combinations of basic services from the service categories in the TOGAF TRM that do not conflict. The combination of services are again tested to ensure support for the applications. This is a pre-requisite to the later step of defining the architecture fully.

The constraints output from Step 2 can provide more detailed information about:

• Requirements for organization-specific elements or pre-existing decisions (as applicable)

• Pre-existing and unchanging organizational elements (as applicable)

• Inherited external environment constraints

Where requirements demand definition of specialized services that are not identified in TOGAF, consideration should be given to how these might be replaced if standardized services become available in the future.

For each Architecture Building Block (ABB), build up a service description portfolio as a set of non-conflicting services. The set of services must be tested to ensure that the functionality provided meets application requirements.

Inputs

The inputs to Step 4 are:

• Business Architecture V2

• Technology Architecture V0.3

• Technical Reference Model (TRM) (see Book 3: Technical Reference Model)

• Standards Information Base (SIB) (see Book 3: Standards Information Base)

Activities

Key activities in Step 4 include:

1. Produce affinity grouping of services

2. Cross-check affinity groups against needs

3. Document service description portfolio for each ABB, cross-checking for non-conflicting services

4. Document change requests to architectures in the Architecture Continuum

Outputs

The outputs of Step 4 are:

• Technology Architecture V0.4

  • Technology Architecture - target services (a description of the service portfolios required, also known as an Organization-Specific Framework)

  • Technology Architecture - change requests and/or extensions or amendments to be incorporated in an organization-specific Architecture Continuum