MIS 3360 Ch 12 System Implementation and Maintenance

system implementation

-convert final physical system specifications into working and reliable software

-document work that has been done

-provide help for current and future users

maintaining information systems

-obtaining maintenance requests

-transforming requests into changes

-designing changes

-implementing changes

implementation

involves coding, testing, installation, documentation, training, and support

deliverables of coding

code and program documentation

deliverables of testing

test scenarios (test plan) and test data & results of program and system testing

deliverables of installation

user guides, user training plan, and installation and conversion plan

audience for final documentation

-information systems personnel who will maintain the system throughout its productive life

-people who will use the system as part of their daily lives

user training

application-specific

general for operating system and off-the-shelf software

software application testing

-a master test plan is developed during the analysis phase

-during the design phase, unit, system, and integration test plans are developed

-actual testing is done during implementation

-written test plans provide improved communication among all parties involved in testing

static technique

the code being tested is not executed

dynamic testing

involves execution of the code

automated testing

computer conducts the test

manual testing

the people complete the test

inspections

testing technique in which participants examine program code for predictable language-specific errors

walk-throughs

should be done frequently when pieces of work are reviewed and before formal testing, is an informal process

desk checking

testing technique in which the program code is sequentially executed manually by the reviewer

unit testing

process of testing each module alone in an attempt to discover any errors in its code

integration testing

process of bringing together all of the modules that a program comprises for testing purposes. modules are typically integrated in a top-down, incremental fashion

system testing

bringing together of all of the programs that a system comprises for testing purposes. programs are typically integrated in a top-down, incremental fashion

stub testing

technique used in testing modules, especially where modules are written and tested in a top-down fashion, where a few lines of code are used to substitute for subordinate modules

testing harness

automated testing environment used to review code for errors, standard violations, and other design flaws

refactoring

making a program simpler after adding a new feature

-eXtreme programming is a technique used in refactoring

acceptance testing

process whereby actual users test a completed information system, the end result of which is the users’ acceptance of it

alpha testing

user testing of a completed information system using simulated data

beta testing

user testing of a completed information system using real data in the real user environment

tests in alpha testing

recovery testing, security testing, stress testing, performance testing

direct installation

changing over from the old information system to a new one by turning off the old system when the new one is turned on

-users at the mercy of the new system

-very risky installation

-least expensive installation

parallel installation

running the old information system and the new one at the same time until management decides the old system can be turned off

-safest approach but very expensive

-outputs are compared with each system

single-location installation

trying out a new information system at one site and using the experience to decide if and how the new system should be deployed throughout the organization

-also called a pilot installation

-considered a middle-or-the-road approach

-once successful then rolled out to entire company

phased installation

changing from the old information system to the new one incrementally, starting with one or a few functional components and then gradually extending the installation to cover the whole new system

maintainance

obtaining maintenance requests

transforming requests into changes

designing changes

implementing changes