If the filter hasn't been changed regularly, the furnace hasn't been working efficiently and it may not last for its expected life span.
In the late 1980s and into the 1990s, as service was improving, transit officials combined engineering and mechanical investigations to unearth persistent problems — say, the same electrical flaw or a part that wore out before its expected life span.
You're supposed to amortize the purchase price of the annuity over its expected life span, that being a function of mortality tables.
The U.S. space telescope, scheduled to be launched late next year, will track the comet back into the far reaches of the solar system during its 17-year expected life span.
These long-lasting, ready-to-use, pre-treated mosquito nets require no further treatment during their expected life span of three to five years.
The assessment, conducted this year by a Philadelphia architectural and engineering firm, found that the building was "in serious need of attention and renovation" and that its heating, air-conditioning and plumbing systems, as well as its electrical circuitry, had outlived their "expected life span".
A limitation of this study was the use of expected life span (estimated from age- and gender-specific life expectancies) for the 70%% of subjects who were still living.
Perhaps not coincidentally, the early part of this week also included Jan . 18 the most depressing day of 2010, according to a formula invented by a Welsh psychologist that takes into account the expected life span of New Year's resolutions, the decay of the holiday glow, the arrival of its attendant credit card bills and other variables.
All now have nearly reached their expected life span.
The data continued the longest sustained decline in expected life span at birth in a century, an appalling performance not seen in the United States since 1915 through 1918.
