New orders
Problem/Context
In a replacement project or enhancement project the existing system has a steady stream of new orders, requests, cases to be handled, etc (hereafter referred to as orders).
Solution
Develop enough features in the new system to support new orders of the simplest type. Add a gateway that directs new orders of the appropriate type to the new system. This pattern can be used together with the Synchronized database or Replicated database patterns in order to make base data available to the new system.
Strengths
- Greatly reduced MRP in some situations
Weaknesses
- The frequency of new orders must not be too high or too low. If the frequency is too high the MRP will become large. If new orders are rare there will be too little feedback from having the release in production.
Examples
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An internet shop could funnel purchases that are to be invoiced to the new system while letting the existing system handle credit card purchases.
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This pattern was evaluated in the Book club system.