Horacio D. Rozanski , chief operating officer of McLean-based contracting giant Booz Allen Hamilton, has been tapped to become president of the contracting giant starting Jan. 1.

Ralph W. Shrader , the company’s chairman and chief executive, previously held the president title as well.

Booz Allen said that Rozanski, who has served as COO since 2011, will continue to report to Shrader. Rozanski joined Booz Allen in 1992, became chief personnel officer in 2003 and was named chief strategy and talent officer in 2010.

Contract vehicles on the rise

As defense spending has declined, there are signs that the Pentagon is increasingly relying on large, sweeping contract vehicles to buy its goods and services, according to a report issued earlier this month by the Center for Strategic and International Studies.

The report, which tracked Pentagon contract spending from 2000 to 2012, found that the use of definitive contracts has declined markedly as the Defense Department has upped its reliance on contract vehicles, with indefinite requirements. Some of these vehicles operate like hunting licenses; contractors must first win a spot on the contract to compete for future orders.

At the same time, competition is in some cases on the rise. The percent of contract dollars awarded with three or more bidders has grown from 25 percent in 2000 to 34 percent in 2012.

CSIS found that fixed-price contracting has been the predominant pricing mechanism for defense contracts from 2000 to 2012, typically accounting for at least 60 percent. From 2011 to 2012, the share of contract awards using the fixed-price mechanism (as opposed to contracts that use less certain pricing formulae) jumped to 68 percent from 65 percent, a move the report called “small but real.”

The report also tracked the top 20 Defense Department contractors. The top five — Lockheed Martin, Boeing, Raytheon, General Dynamics and Northrop Grumman — remain the same in 2012 as they were in 2002. But local contractors DynCorp International and Booz Allen Hamilton, not on the list in 2002, now make the cut.

Orbital launch pushed to 2014

Dulles-based Orbital Sciences said earlier this month that its planned launch of its commercial cargo resupply mission to the International Space Station has been postponed until next year.

The company has a deal with NASA to launch unmanned space modules that will deliver supplies to the station.

The launch was delayed at the direction of NASA, which must repair a faulty pump module on the International Space Station, Orbital said. The company said the next launch attempt will occur no earlier than Jan. 7.

Engility revamps to cut costs

Chantilly-based Engility, which was spun off from L-3 Communications last year, said this month that it is restructuring again to cut costs. The company has remodeled itself as a government services contractor, with a particular focus on keeping its prices low.

In its latest move, Engility is combining two operating units into one focused on engineering and program management services. John Heller , Engility’s chief operating officer, is leaving the contractor, the company said. (Arlington-based contractor Pacific Architects and Engineers , better known as PAE, has named Heller its chief executive).

Engility said it has also put in place other organizational changes and budget reductions to cut costs in 2014.

GAO rejects EVI protest

The Government Accountability Office has denied a protest filed by Springfield-based Emergency Vehicle Installation against a National Geospatial-Intelligence Agency purchase order issued to Alexandria-based Goldbelt Wolf for modification of police emergency vehicles.

EVI had argued that the agency improperly evaluated its quotation, but the GAO disagreed.