Before I.B.M.'s advance, while digital computing technologies were integrated onto single silicon chips, analog functions were performed by larger and more costly separate components.

The guidance system is constructed so that the most sophisticated and costly components, such as a gyroscopic coordinator, electronic units and an onboard battery, are excluded from the missile.

All three rivals possess a "switching technology" - the costly and critical component that is at the hub of all telephone service.

Many experts also predict that construction could take much longer than now foreseen given the difficulty of coordinating multiple suppliers of costly and highly technical components in many countries.

Siemens spokesmen said the company would focus on the home market next year, when the cost of liquid crystal displays, the single most costly component in most Web pads, is expected to drop.

Because these are also the most costly components, take a long-term view; add plants you can afford now and work on the gaps next year.

In early homebuilt sets, the earphones were the most costly component.

Rather, in general, Apple has chosen to build its Mac line around higher-end computers with better - and more costly - components.

But cement is a costly component and has a relatively powerful impact on the environment.

Parents of young children will need day care, a costly component of welfare-to-work programs.