IBM Branch Transformation Toolkit 5.1 Migration and Usage Guidelines

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A real-world situation involves a branch employee starting a workstation,

inputting and validating the customer's data before a withdrawal operation is

performed. In our sample, we provide implementation of these actions, in

addition to a customer search view to initialize the environment.

After the environment is started, a graphical interface prompts the branch

employee to edit information in the entry fields of the view, such as the

customer's account number and the withdrawal amount.

After the required information is supplied, the workstation performs initial

validation, requests the data from the system, and data is then sent to the server.

The server should do the following:

򐂰 Create a journal record.

򐂰 Send formatted data to the host.

򐂰 Receive a host reply.

򐂰 Send a reply to the client process and update the last record with the host

reply.

The other services that can be developed to improve this application, although

not included in this book, are, printing and delivering a receipt to the client, and

updating the cash drawers in order to keep control of the cash amount.

8.1.2 Developing the system specification

Developing the system specification is usually the first step to system

development. It minimizes the gap between the application scenario and the

implementation.

Specification includes architecture, component interactions, message definition,

and internal data structure.

Architecture

For the scenario in our sample, we built a Web application using Branch

Transformation Toolkit v5.1 to achieve the goal. A typical architecture of this kind

228 IBM Branch Transformation Toolkit 5.1 Migration and Usage Guidelines

of application includes WebSphere Application Server, DB/2 database server,

Host, that is, S/390®, and Web Browser, as shown in Figure 8-1.

Figure 8-1 The typical architecture of a Branch Transformation Toolkit Web application

In our application, we used two services:

򐂰 Journal service

This service is based on a database and keeps information about the

operations performed during a predefined period of time. We simulated this

service with a dummy service named DummyJournal. In the second stage,

we substituted the DummyJournal with a real journal service that accesses a

real DB/2 database.

򐂰 Host transaction service

This service is used to send and receive formatted data to and from a

simulated host. We simulated a SNA LU0 protocol with a dummy host

communication service. This dummy service was named

DummyLu0SnaSession.

Component interactions

Here we set up a withdrawal operation. There are three stages to completing a

withdrawal operation.

Stage 1

A teller uses a Web browser to connect to a Branch Transformation Toolkit v5.1

application to perform a withdrawal operation. An input form is displayed in the

browser, requesting the account number and the amount.

WebSphere Software

Host

Transaction Service

Host

Journal

Service

BTT 5.1

Application

Web Client

Request

Reply

Request

Reply

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Stage 2

After obtaining the customer’s account number and the amount details, the teller

inputs these two numbers and submits the request. The application then

initializes the transaction, appends Date, Session, and Branch data to withdrawal

data (Account Number and Amount). Journal service takes this formatted data

and stores it as the log of this transaction in the database.

Stage 3

When the journal service is completed, the application sends the formatted data

to the host to execute the real withdrawal operation. The host sends the reply

after completing the execution. The result is displayed in the Web browser.

Message definition

When you understood fully the functionality of the application, you should

determine the required host transaction messages and the data intended for the

electronic journal service.

Host transaction messages

The host transaction messages are:

򐂰 Requests sent to the host include the following:

– A static transaction header code, for example, Tx02

– Account number

–Date

– Amount

– Branch identifier

򐂰 Replies from the host include the following:

– Reply code

– Updated account balance

– Error message

Electronic journal messages

The electronic journal messages include:

򐂰 The data that should be stored prior to sending data to the host include the

following:

– User identification

– Terminal identifier

– Transaction data being sent to host

򐂰 The data that should be stored after receiving the host reply, include the

following:

– Reply code