NonStop Systems Introduction

Introduction
NonStop Systems Introduction—527825-001
1-8
The ZLE Architecture
Looking at Figure 1-3, note that the ZLE framework resembles a wheel, with the
various operational business systems at the outer rim and the ZLE hub at the
center. The operational systems include all of the existing legacy systems of a
business, running applications such as reservation systems, order entry, inventory, and
all the other applications required for the operation of the business. The applications
are likely the products of multiple software vendors, and the computers may also be
the products of different hardware vendors. Systems from IBM, Unisys, Sun, and so
on, could be running applications such as SAP, PeopleSoft, Bann, Siebel, or even
custom applications developed in-house. The applications may have their own
databases as well.
At the center of the ZLE framework is the ZLE hub, consisting of one or more NonStop
servers. (It is possible to configure a hub using NonStop servers interconnected with
other systems! This is a distinct advantage for corporations with an existing
infrastructure). Hosted on the NonStop servers are the two major components of the
ZLE framework: the enterprise application integration (EAI) environment and the
ZLE data store.
The ZLE data store, or simply data store, is a relational database that serves as a
central repository for business-related data. The data store contains current data from
the business’s operational systems; it provides a single, up-to-the minute, integrated
view of the entire corporation, and is able to provide current data to any of the business
applications that need it. It must contain data at a very detailed level. (The data store
doesn’t contain ALL the data from the operational systems; when the data store is
designed, decisions must be made as to what subset of the data is actually required by
the ZLE applications and the application integration efforts). For example, various
businesses might have the following needs for each customer:
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A telecommunications company might need a detailed record of every call made.
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A bank might need a record of every load payment, ATM withdrawal or deposit,
every credit card purchase, every check written, and so on.
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A retailer might need a record of every item purchased, the payment type (cash,
check, or credit card), and so on.
The data store provides a single view of the enterprise and of the customer. For
example, consider the case of a telecommunications company in the business of
selling phone lines through customer service representatives.
A customer calls the service center to request a new line. The service representative
would like to close the deal while the customer is still on the line. In order to do that,
the representative needs customer information, which resides in the master customer
database. The representative also needs access to a provisioning system, which can
provide a schedule (for line installation) and the new phone number.
On the basis of that information, a billing system needs to provide pricing information
and generate a bill. The challenge is how to give the customer representative access
to these different systems running on different platforms and databases, with each
system largely independent and relying on its own view of the customer. A customer
representative might have access to all these systems and might be able to navigate