Types of Instances in implementation

Hi all,

today let us discuss something on the instances which a consultant normally work on...
Instance is an address for a location where Applications database is stored.
We might have heard of many instances such as Vision, Test, Development,CRP I, CRP II, UAT, Production etc.... but apart from the name there is no change in the behaviour of any of the Instances.
All instances carry the same technical features and functional setups, no difference what so ever in any of them, but why we call it by different names then ?
The different instance names are given based on the purpose for which it is used. Every instance is created with the same features and specifications, only naming is done based on the usage or the purpose.
We will see the standard or common purposes for which different instances are used in
an implementation.

Test Instance
It is a fresh instance which is used by the Implementation team to try out new setups and work arounds as per the clients business specifications and arriving at final solutions. Apart from that test instance is used for testing the performance of installation as well as other factors. The life of this instance starts from the first day of kick off and ends when the production begins or system has gone live.

Development Instance
It is also a fresh instance when installed, but more or less it replicates the test or Production instance (normally cloned). The purpose is to make constant development in the current business process and the system performance and working out new methods in solving critical bottlenecks with the current system. The life of this instance is infinity, since there is no end to development, it is an ongoing process, it continues even after the system has gone live.

Production Instance
It is a fresh instance installed with an intention to share it with all the users of the client with fine tunning. This instance is different from Test and Development with respect to the number of users, size of the database, security features etc. The life of the production instance begins when the User Acceptance testing is done, and it continues till the company is in existence.

Vision Instance
It is different from all other instances because the installation comes with the data, whereas all other instances are Fresh. Even though there is no particular necessity to have this instance in an real time scenario, but it is better to have a vision instance always for the following reasons:

1) It serves as a practice for the DBA to find out the installation problems that occurs due to hardware failures.
2) Functional consultant often try out a small business scenarios to find out solutions, in order to try out these scenarios, they need to do all the mandatory setups in an instance then only they can perform it. If they had vision instance, they can use the existing setups to try out thier business scenarios
3) It also acts as a tutor to the Functional Consultants in case they are lost in performing critical setups.

Regards
Karthikeyanp1981@gmail.com