Time variance
Encyclopedia
Time variance is the ability to remember historic perspectives. The requirement is to be able to know how something was classified or who owned something and how this changed as time passed.
For the context of time and frequency and qualification of oscillators and amplifiers the technical terms time deviation
and time variance
is defined.
to report
pre- and post-change information together in a meaningful context is very expensive and time-consuming. Couple that with the pressure to rapidly meet other business
requirements, and with the inability for any of us to predict change (especially at system design time!), and you can see why the time-variant reporting requirement is often ignored. But at what expense? The real-life case below illustrates the value of time-variant reporting:
A beverage company paid rebates to customers at year-end, based on ownership of customer sites at year end. The sales data warehouse did not reflect customers selling sites to one another throughout the year, resulting in mis-payments and a multi-million dollar customer service dilemma.
For regulatory compliance and other reasons, data warehouses must remember how things were in the past because at some point business people will expect to be able to be report on them that way.
For the context of time and frequency and qualification of oscillators and amplifiers the technical terms time deviation
Time deviation
TDEV is a metric often used to determine an aspect of the quality of timing signals in telecommunication applications and is a statistical analysis of the phase stability of a signal over a given period of time...
and time variance
Time deviation
TDEV is a metric often used to determine an aspect of the quality of timing signals in telecommunication applications and is a statistical analysis of the phase stability of a signal over a given period of time...
is defined.
Understanding time variance
Future change, be it organizational, regulatory or geographical is hard to conceive. In 1988, who imagined that within a few years, Yugoslavia and East Germany would cease to exist? Enabling a data warehouseData warehouse
In computing, a data warehouse is a database used for reporting and analysis. The data stored in the warehouse is uploaded from the operational systems. The data may pass through an operational data store for additional operations before it is used in the DW for reporting.A data warehouse...
to report
Report
A report is a textual work made with the specific intention of relaying information or recounting certain events in a widely presentable form....
pre- and post-change information together in a meaningful context is very expensive and time-consuming. Couple that with the pressure to rapidly meet other business
Business
A business is an organization engaged in the trade of goods, services, or both to consumers. Businesses are predominant in capitalist economies, where most of them are privately owned and administered to earn profit to increase the wealth of their owners. Businesses may also be not-for-profit...
requirements, and with the inability for any of us to predict change (especially at system design time!), and you can see why the time-variant reporting requirement is often ignored. But at what expense? The real-life case below illustrates the value of time-variant reporting:
A beverage company paid rebates to customers at year-end, based on ownership of customer sites at year end. The sales data warehouse did not reflect customers selling sites to one another throughout the year, resulting in mis-payments and a multi-million dollar customer service dilemma.
For regulatory compliance and other reasons, data warehouses must remember how things were in the past because at some point business people will expect to be able to be report on them that way.