Pattern for Controled Evolution (PCE)
Ensures coherent evolution to capabilities and supporting service components of the architecture with changing goals
Identity : Controled Evolution
Intent : Ensuring coherent evolution to capabilities and services of the architecture according to changes captured on business goals.
Solution Step 1 - What are capability components to be impacted by the change: Changes are assigned to appropriate capability and service components able to control directly achievement of related behaviours vertically inside each capability and horizontally between capabilities.. This ensures coherent propagation and deployment of the changes.
Solution Step 2 - How these components should be impacted: Impacts of changes are traced throughout the underlying structures of target capabilities to help them evolve coherently with assigned responsibilities..
Explanation Step 1 :
The first step assists analysts and designers in the identification of capability components able to support changes. In order to confering to the business and IT architecture a coherent evolution according to changing goals, underlying strategic responsibilities are to be assigned to appropriate capability structures able to host them in order to control directly their evolution.
For instance in the figure below that shows assignment of responsibilities to capabiliities due a changing goal, two subsequent strategies namely Turn Visitors into Buyers and Incite Customers to Purchase Complementary Products are assigned to CRM System Capability. Objectives that quantify expected outcome for the first strategy are also indicated.
Figure 1 : New responsibilities are assigned to capability controllers of the existing business architecture being driven by goals
Explanation Step 2 :
Now, in order to adapt each target capability component to assigned responsibilities, we focus on their internal and external capability components and how they should be impacted by the change.
PROPAGATION OF THE CHANGES WITHIN THE TARGET CAPABILITY
On the basis of this initial outline of impact analysis, internal and external components of this target capability may be precisely determined further by decomposing goals tll gathering requirements.
There are different manners for mapping changing requirements onto the existing architecture of the system.
A possible solution is to use the ArchiMate Goal-Realization Viewpoint that allows identification of requirements on the basis of Drivers, Goals and sub-goals of the architecture. On the other hand, emerging requirements help to discover initial components of target capabilities able to realize them.
Such an hierarchy is shown below where two internal sub-capabilities of the target CRM System capability are discovered.
Figure 2 : An initial structure of sub-capability components of the business architecture may be discovered using the ArchiMate Goal-Realization Viewpoint
Before proceeding to populate these sub-capabilities using business functions, we will focus on risks related to their realization and actions to mitigate them. The worksheet below provides for Managing Visitor Registration... sub-capability some risks; impacts and actions to mitigate these risks.
Figure 3 : Excerpts of the Risk Identification and Mitigation Assessment Worksheet to identify potential business functions
On the basis of actions that can mitigate risks of Managing Visitor Registration... sub-capability, we start to populate it below using business functions.
Figure 4 : Business functions identified shown with their internal processes are controled by the capability orchestrator
Now, in order to understand more about services that support capabilities and govern access to its functions, we need to focus on their expected service level (SLE) by function.
The diagram above illustrates some SLE on the basis of requirements and risks we have provided on the related figures and worksheet above.
Figure 5 : Business functions identified shown with their internal processes are controled by the capability orchestrator
The following patterns discuss process modeling approaches to implement assigned responsibilities to the target capability.
- PTAL (Traceable Abstraction Layers) to describe related business processes and assign roles to actors in realizing them.
- PUBS-AL (Using Business Service Specifications from the Applications) to allow users of the IT applications to invoke such business functions depending on different channels and their application choices.
Strengths of the pattern PCE :
This pattern helps to ensure coherent evolution to capabilities of the architecture according to changes captured on business goals. It does not only execute a vertical impact analysis by focusing on the sub-components of the target capabilities but also highlights impacts on other capability components by doing a horizontal impact analysis on their functions.
Relationships : The pattern PCE requires later contributions from patterns PTAL (Traceable Abstraction Layers) and potentially PUBS-AL (Using Business Service Specifications from the Applications). Its dependencies with other patterns of the Goal & Capability-Driven SOA (GD-SOA) backbone are illustrated below.