s do not scale with change in requirements leading to higher costs for enhancements and integration to support changes in technology. The impact of having legacy process and rigid systems becomes evident in a multiservice, multitechnology, and multi- vendor environment where adaptability and interoperability are key concerns, and mergers and acquisitions are quite common. These can also result in poor customer service because of poorly integrated systems with inconsistent data. The NGOSS approach to this problem is to adopt the lean operator model in telecom industry, which has already proved its effectiveness in automobile, banking, and retail industries. The main attributes of a lean operator are reduced operational costs and a flexible infrastructure. The reduced cost of operations in a lean operator model is achieved with high levels of automation. Seamless flow of information across modules is a major requirement of the lean model, which can be achieved with standard information model and well-defined interfaces for NGOSS Enterprise application integration Legacy Loosely coupled Distributed Figure 21.1 Changes in architecture. interaction. The seamless flow of data also ensures that data is consistent leading to better customer service. Customer self-care is also suggested to bring down opera- tional costs, reducing the need for more customer desk executives. Commercial off the shelf products that has already been a valuable tool for ease of integration is another factor to be looked into for reducing operational costs. When the business and technical requirements change, the infrastructure should be flexible enough to adopt the changes. The faster the resources can adopt a change in requirements the more rapid will be the time to market. This means significant reduction in the service development and delivery time. The adoption of lean prac- tices should be done without compromise in service quality. The OSS architecture has migrated over the years from legacy to loosely coupled and finally to a distributed