IFS 310 Module 13 Implementation and Support Construction

IFS 310: Module 13 Implementation and Support - Construction, Conversion and Maintenance of the New System

IFS 310: Module 13 What is Systems Implementation? • Systems implementation is the construction of the new system and the delivery of that system into production (meaning day-to-day operation).

IFS 310: Module 13 The Construction Phase of Systems Implementation • The purpose of the construction phase is twofold: – To build and test a functional system that fulfills business and design requirements, and – To implement the interfaces between the new system and existing production systems.

IFS 310: Module 13 Build and Test Networks • The purpose of this activity is to build and test new networks and modify existing networks for use by the new system. • The key input is the network design requirements defined during systems design.

IFS 310: Module 13 Build and Test Databases • The purpose of this activity is to build and test new databases and modify existing databases for use by the new system.

IFS 310: Module 13 Install and Test New Software Package • The purpose of this activity is to install any new software packages and make them available in the software library. – The applications programmer will complete the installation and testing of the package according to integration requirements and program documentation that was developed during system design.

IFS 310: Module 13 Write and Test New Programs • The purpose of this activity is to write and test all programs to be developed in-house. • If modules are coded top-down, they should be tested and debugged top-down and as they are written.

IFS 310: Module 13 Testing a New Program – There are three levels of testing to be performed: stub testing, unit or program testing, and systems testing. • Stub testing is the test performed on individual modules, whether they be main program, subroutine, subprogram, block, or paragraph. • Unit or program testing is a test whereby all the modules that have been coded and stub tested are tested as an integrated unit. • Systems testing is a test that ensures that application programs written in isolation work properly when they are integrated into the total system.

IFS 310: Module 13 The Delivery Phase – Conduct a system test to ensure that the new system works properly. – Install databases to be used by the new system. – Provide training and documentation for individuals that will be using the new system. – Prepare a conversion plan to provide a smooth transition to the new system. – Convert from the old system to the new system and evaluate the project and final system.

IFS 310: Module 13 Conduct System Test • The purpose of this activity is to test all software packages, custom-build programs, and any existing programs that comprise the new system to ensure that they all work together.

IFS 310: Module 13 Install Databases • The purpose of this activity is to populate the new systems databases with existing data from the old system.

IFS 310: Module 13 Train System Users • Provide training and documentation to system users to prepare them for a smooth transition to the new system.

IFS 310: Module 13 Conversion • Prepare a detailed conversion plan to provide a smooth transition from the old system to the new system. • Convert to the new system from the old system and evaluate the project experience and final system.

IFS 310: Module 13 Common conversion strategies – Plunge (Direct Changeover) – Parallel conversion – Phased (Gradual) conversion – Pilot (Modular prototype) conversion – typically in a single location

IFS 310: Module 13 What is Systems Support? • Systems support is the on-going maintenance of a system(s) after it has been placed into operation. This includes program maintenance and system improvements. • Systems support often requires developers to revisit activities typically performed in systems analysis, design, and implementation.

IFS 310: Module 13 Systems Maintenance - Correcting Errors – Regardless of how well designed, constructed, and tested a system or application may be, errors or bugs will inevitably occur. – The correcting of bugs is called system maintenance, or program maintenance.

IFS 310: Module 13 System Recovery - Overcoming the “Crash” • A system failure is inevitable. – It generally results in an aborted or ``hung'' program (also called an ``ABEND'' or ``crash'') and possible loss of data. – The systems analyst often fixes the system or acts as intermediary between the users and those who can fix the system.

IFS 310: Module 13 Database Backup and Recovery • Data in a database may be lost or corrupt by invalid or partial update due to the crash. • Backup/Recovery Techniques – Roll back: logging (taking a backup copy) of beforeimage (image of DB before the transaction), and “rollback” the image when data are lost. – Roll forward: perform transaction on the image (master is intact), upon successful transaction, dump the image onto the master (roll forward).

IFS 310: Module 13 End-User Assistance • No matter how well users have been trained or how well documentation has been written, users will require additional assistance. – The systems analyst is generally on call to assist users with the day-to-day use of specific applications.

IFS 310: Module 13 Systems Enhancement and Reengineering • Adapting an existing system to new requirements is an expectation for all newly implemented systems. • Adaptive maintenance forces an analyst to analyze the new requirement and return to the appropriate phases of systems analysis, design, and implementation.

IFS 310: Module 13 The Year 2000 and Systems Support • The year 2000 problem was the potential of triggering widespread computer application disasters across many corporations.