Direct changeover
Encyclopedia
Direct changeover is one of the methods to change from an existing system to a new one.
This is the simplest methods of changeover. Imagine a new checkout system
for a supermarket. If the implementation is done by direct changeover, then the supermarket will be closed for one night, all the old checkouts will be taken out, the new ones will be installed and the supermarket will be ready to open the next day. Although this is a simple method, it takes a lot of planning. All the files have to be ready to load, all the workers need to have been trained in advance and the system must have been properly tested. If the checkouts do not work when they are switched on, the store will have to close because they cannot go back to the old system.
This is how the UK stock market was computerized in the 1980s. The old market closed on Friday night and the computers were all switched on the following Monday morning. Unfortunately, there was an error in the software, which made all the computers sell shares and carry on selling them. By the time human beings had intervened to stop the computers, half of the value of companies had been wiped off the stock market and many people had been ruined.
Other methods of changeover include phased implementation
and parallel running
.
This is the simplest methods of changeover. Imagine a new checkout system
Point of sale
Point of sale or checkout is the location where a transaction occurs...
for a supermarket. If the implementation is done by direct changeover, then the supermarket will be closed for one night, all the old checkouts will be taken out, the new ones will be installed and the supermarket will be ready to open the next day. Although this is a simple method, it takes a lot of planning. All the files have to be ready to load, all the workers need to have been trained in advance and the system must have been properly tested. If the checkouts do not work when they are switched on, the store will have to close because they cannot go back to the old system.
This is how the UK stock market was computerized in the 1980s. The old market closed on Friday night and the computers were all switched on the following Monday morning. Unfortunately, there was an error in the software, which made all the computers sell shares and carry on selling them. By the time human beings had intervened to stop the computers, half of the value of companies had been wiped off the stock market and many people had been ruined.
Other methods of changeover include phased implementation
Phased implementation
Phased implementation is a method of changing from an existing system to a new one. Phased implementation is a changeover process that takes place in stages. Think of a supermarket for example. Imagine that only the vegetable section is changed over to the new system while the rest carries on with...
and parallel running
Parallel running
Parallel running is one of the ways to change from an existing system to a new one.During changeover, a new system and an existing system run side by side. To input the same data and perform the same processes, compare their output and prove the reliability of the new system...
.