Download java - saic - netwarcom

JAVA - SAIC - NETWARCOM
Science Applications International Corporation (SAIC)
Naval Network Warfare Command (NETWARCOM)
Engineering Operational Sequencing System (EOSS)
VAX-BASIC to Java 2 Enterprise Edition (J2EE)
History: The US Navy, under the auspices of
the Navy E-Business office, undertook a major
pilot program to assess the feasibility and
business value of using commercial automated
transformation software to convert legacy code
into modern, object oriented, NMCI compliant
code. The Navy selected a unique widely used
Navy legacy information system written in VMS
VAX BASIC for the pilot. The Engineering
Operational Sequencing System (EOSS)
provides standard propulsion plant procedures
and operating criteria for every ship in the U.S.
Navy fleet. EOSS was chosen by the Navy
Functional Area Manager (FAM) office for its
extreme complexity, and the perception that
automated modernization of EOSS into NMCI
compliant code would be extremely difficult.
Science Applications International Corporation
(SAIC), prime contractor, awarded The
Software Revolution, Inc. (TSRI) a sole source
contract, under the auspices of the Space and
Naval Warfare System Command (SPAWAR),
to modernize EOSS.
Challenge: To perform the requested documentation and transformation, TSRI software
engineers were required to make two necessary tool adjustments to the JANUS™ Intermediate
Object Model (IOM), they created a VAX-BASIC gateway and they included J2EE as a modern
target. TSRI also made several design adaptations to preserve EOSS functionality while
modernizing its architecture.
System Interfaces: The TSRI modernization effort preserved two types of interface between
the modernized EOSS Accountability System and the external systems with which it interfaced.
• The first was the User interface, which provided user telnet sessions via remote
terminals. The user terminal interfaces were replaced by web browser connections,
made within a local area network through a virtual private network (VPN), from
external Internet sites using SSL. HTML forms presented by web server scripts
provided screen I/O similar to the original telnet sessions.
• The second type was the FTP interface, transferring to and from various external
systems.FTP connections in the legacy system were used to transfer text files to and
from EOSS. The modernized EOSS application produces and reads files required for
the FTP interfaces in the same format as the legacy application. Thus the FTP
interface was preserved. Systems formerly using FTP to push files to EOSS were
changed to point to the new Sun Server hosting the modernized EOSS application.
The modernized EOSS application uses a Java FTP library to push FTP files to the
same destination as the current EOSS application.
System Architecture: For modularity and flexibility, TSRI designed an n-tier architecture for
the modern system. Components residing in the first 4 tiers were implemented on a Sun Solaris
server and those in the final tier run on a Windows IIS server. The existing EOSS system was
transformed to the new design as follows:
• Original VAX-Basic EOSS code was transformed into Java, preserving exact
functionality
• User telnet sessions and terminal I/O were replaced by SSL web connections and html
pages
The VAX flat file database system was replaced by an Oracle relational database
accessed through a JDBC based API
• Scheduled automated processes on the VAX system were replaced by UNIX system
“cron” scheduled processes
• FTP sessions to and from external sessions work the same way as before, using a
Java FTP library
(A) The Data Tier was implemented in the form of a single Oracle 8i. The database was
implemented using standard data types and table formats so that it could be re-hosted to other
database servers such as Oracle 9i or Microsoft SQL Server.
(B) The Data Access Tier was implemented as the interface layer between the EOSS business
logic code and the Data Tier. It was written in Sun J2EE Java using JDBC. It would perform I/O
operations on the ACDATA database in place of the original VAX flat file operations.
(C) The Business Logic Tier contained all EOSS Java code translated from VAX-BASIC and
any scripts designed to replace other functionalities. Processes, which were separate in the
legacy system, were grouped into a single Java application with logic invoked separately.
These processes are invoked and managed by a master “broker”, enabling multiple
simultaneous, multi-threaded execution instances. This tier interfaces with the Data Access Tier
and the Presentation Tier through API’s isolating the business logic from screen I/O and
database implementation details. All of this is written in Java.
(D) The Presentation Tier encompasses all functionality related to generating the user interface.
To accomplish this, a “Screen API” was written in Java to setup and to manipulate screen I/O
data. Screen I/O and process synchronization data are stored in another database in this tier.
This database is different from the one in the Data Tier, but resides on the same physical
machine and Oracle server. This database provides inter-process communication and
synchronization between this tier and the Web Tier. Communication messages are stored as
rows in a table with columns representing data fields. The Web and Presentation tiers maintain
synchronization and data display continuity through this mechanism.
(E) The Web Tier is a IIS web server running VB Scripts and providing SSL communication with
end user browser sessions. It communicates with the Presentation Tier using ADO.
•
Results: The J2EE modern EOSS system enhanced performance and eased maintenance
over the legacy VAX Basic system. Moreover the new system’s design provides significant
scalability benefits. While the modern EOSS system was implemented on only two servers, the
modular architecture supports further machine distribution to meet future requirements.
NETWARCOM analyzed the 5 year cost savings of TSRI's automated Legacy System
Modernization (LSM). The results were a Cummulative Gross Productivity Savings of $953,000
and a 2.47:1 Return-on-Investment (ROI).