The phrase "a formidable system" is correct and usable in written English.
It can be used to describe a system that is powerful, impressive, or capable of achieving significant results.
Example: "The new software is a formidable system that can handle large volumes of data with ease."
Alternatives: "an impressive system" or "a powerful system".
To outsider investors, the "labyrinth" created by the hedge funds, managers and HSBC subsidiaries named as defendants looked like "a formidable system of checks and balances," said Oren J. Warshavsky, a partner at Baker & Hostetler, the trustee's law firm.
The fortress was surrounded on three sides by deep ravines and defended by a formidable system of walls and ditches.
Polytene chromosome spreads have provided a formidable system for visualization of MSL binding on the male X chromosome (Fig. 2).
Coca-Cola has a formidable system of distribution to thousands of tiendas all over the country, actively encouraging owners to stock their drinks by providing free incentives, such as point-of-sale materials and refrigerators, in return for an exclusivity agreement.
It's many things, including a formidable alerting system for a breaking story; a means of organization; a monitor of global interest levels (Iran trended highest for weeks until Michael Jackson's death) and of media performance; a bank of essential links; a rich archive; and a community ("Twitter is my best friend").
The anticrime drives invigorate and define the darkest corner of China's formidable system of social control, a corner, largely unseen by the broader population, where police brutality is tolerated, even encouraged.
It had a polished stainless-steel frame, a hand-molded fiberglass interior, airbrushed leather seats and a formidable stereo system.
But Delaware has created a formidable legal system where investors feel relatively comfortable that their interests are held in high standing.
Poverty reduction strategies are in place in most poor countries and a formidable monitoring system has been set up to track progress toward the Millennium Development Goals at global and country levels.
Greek border fortifications had been adapted for the terrain and a formidable defence system covered the few available roads.
The horseshoe crab has been dubbed a "living fossil" with several hundred million years of evolutionary success, indicating that it harbors a formidable antimicrobial system.
