three-tier

three-tier

(architecture)
A client-server architecture in which the user interface, functional process logic ("business rules") and data storage and access are developed and maintained as independent modules, most often on separate platforms.

Apart from the usual advantages of modular software with well defined interfaces, the three-tier architecture is intended to allow any of the three tiers to be upgraded or replaced independently as requirements or technology change. For example, an upgrade of desktop operating system from Microsoft Windows to Unix would only affect the user interface code.

Typically, the user interface runs on a desktop PC or workstation and uses a standard graphical user interface, functional process logic may consist of one or more separate modules running on a workstation or application server, and an RDBMS on a database server or mainframe contains the data storage logic. The middle tier may be multi-tiered itself (in which case the overall architecture is called an "n-tier architecture").
References in periodicals archive ?
* SKODA AUTO has launched a three-tier qualification programme for skilled staff
THREE-TIER CHELSEA PLANTER Now PS29.99 plus PS4.95 p&p
ISLAMABAD -- The education authorities in the federal capital on Monday unveiled a three-tier plan to enrol all out-of-school children in the city by May.
Governors back a three-tier governance structure, CoG Chairman Wycliffe Oparanya has said.
figure By JUSTUS OCHIENG' Governors have endorsed a proposal for the formation of a three-tier system of government, saying it will strengthen devolution.Council of Governors (CoG) chairman Wycliffe Oparanya on Tuesday told the Nation they would push for the creation of regional governments.
In the report available with The Nation, the committee recommended to the government that the three-tier taxation system on cigarettes should be removed and reverted back to the two-tier system.
The representatives of Sindh including member IRSA and secretary irrigation raised the issue of application of three-tier formula for distribution of water shares among the provinces and said it was in violation of the 1991 water accord.
Irsa, however, decided with majority including three provinces of Punjab, Balochistan and KP and the federal government to set provincial shares under three-tier basis.
Taking cognizance of hefty decrease in tax collection from the tobacco sector, especially after the introduction of the three-tier tax system on cigarette price by the FBR in May last year, the Public Accounts Committee (PAC), National Assembly and Senate Standing Committee on Finance and Health etc had earlier taken up the issue and discussed in detail the ups and downs of the newly introduced three-tier tax structure on cigarette prices that caused a massive decline in revenue collection from the tobacco sector which is a major contributor to the national exchequer.
Summary: Agartala (Tripura) [India], Sept 02 (ANI): Tripura State Election Commissioner G Kameswara Rao on Saturday announced that the by-elections to the 3,386 vacant seats of three-tier gram panchayats, panchayat samities and zilla parishads would be held on September 30.
Thus, the three-tier system may not appropriately inform health care consumers regarding the performance of transplant programs or other medical providers.
Thejudgesobserved that the development may be shared with all other stakeholders including Election Commission of Pakistan and parliamentarians so that the milestone may be achieved in time.InJanuary, Nadra apprised the apex court that a three-tier electronic mechanism named the Internet Voting System for Overseas Pakistanis will be developed at a cost of Rs150 million and within a period of four months.