What should be the approach of taking a SOA implementation? Top down or
Bottom up. Should be start from scratch which some book worm believe is
true or in practice there is any answer to this question - "What should I
do of my existing assets? Should throw away them and start a new SOA
project from scratch? These are the questions I will try to answer from
an architects view point (obviously not from a vendor view point)... There are two approaches to execute SOA top down and bottom up. Top down Also known as green field. This approach is best suited when you are going to implement a new system. Following are some of the activities or steps involved-
Benefits of this approach Helps in scope definition. Capturing of business rules at a high level. Better understand the business context Dependencies can be identified earlier at higher level Interactions between various actors. Complexity within the enterprise in terms of message exchange patterns is known earlier. This was business process driven flavor of top down approach. There is another variance of Top down approach - use case driven. Bottom up Generally this approach is taken for modernization of legacy systems or non SOA systems to SOA eco-system. Following are some activities involved-
This approach not necessarily require business process approach (identification of processes, modeling them and then using services to implement those processes). |