DARIEN, Ill. - In the Army Reserve, everyday responsibilities must go on even when the "boss" isn't there, or when some of its Soldiers deploy.

But what happens when half of a unit deploys from a command headquarters responsible for more than 12,000 Soldiers?

That's the question the 416th Theater Engineer Command (TEC) is working out through a multi-year staff exercise (STAFFEX) process that kicked off this June.

The 416th TEC is headquartered about 25 miles southwest of Chicago, yet it's responsible for the training, operations and missions of approximately 170 units across 27 states west of the Mississippi and Ohio Rivers. If the TEC deploys, those responsibilities continue, in addition to whatever mission they support in a deployed theater.

"Just so we are clear this is not an abstract exercise," said Maj. Gen. Lewis G. Irwin, commanding general 416th TEC. "We need to be able to position ourselves to be a sourcing solution for (two) types of missions."

This STAFFEX is designed to exercise the headquarters to continue its peacetime mission stateside while performing a wartime mission overseas. The headquarters also has the ability to mobilize in support of civil authorities for natural disaster relief efforts and humanitarian aid, both in the U.S. and internationally. This year's STAFFEX was structured as an academic training event focused on military doctrine, allowing leaders from every section to refine their processes and procedures.

The TEC hasn't deployed since Operation Iraqi Freedom (2002-2003) and since then, the Army as a whole has restructured and redesigned its commands and operations. The TEC is using this opportunity to continue to match the ever-changing landscape of the Army and its needs.

"The goal of the STAFFEX is to set the conditions for the entire staff to work together in a deployed environment," said Maj. Justin Kilpatrick, 416th TEC plans officer. "This exercise differentiates from any other 2-star command because we are starting from ground zero ... The goal is to take what we learn here as a base, so that when we go to an exercise or control an exercise and start training for it, we will be ready."

Future STAFFEXs will be mission-focused instead of doctrine-focused. This year's phase serves as a study to help leaders actively shape their responsibilities moving forward.

"Our goal was to go back to the basics, go back to first principles, and ground our staff activities as a theater engineer headquarters in the appropriate doctrine," said Irwin.

This STAFFEX took place as a stand-alone training event at the TEC's headquarters, but future rotations could take place in other parts of the country and involve the 416th TEC in larger training exercises. The ideal end goal for the command group is to embed into a major training exercise, such as a war exercise (WAREX), which includes dozens of units from all over the country, each responsible for different aspects of a war-like scenario, usually lasting one or two weeks. By fiscal year 2017, the TEC hopes to act and validate as a Joint Task Force (JTF) for such an exercise.

"The point is to have achieved the necessary training to put us in position to respond if the Army or Joint Forces needs us," said Irwin.

During this exercise, Soldiers set up the multi-room tent system to simulate a deployment station. The tent was decked with high-end equipment, projection screens, video conference cameras and various computer stations. Army network engineers set up various satellites outside the tent to provide connectivity.

In a deployed environment, the 416th TEC would have three major areas of responsibility: assured mobility, general engineering and geospatial engineering. Assured mobility means the TEC directs construction and combat engineering missions at the strategic level to gain advantage of movement against the enemy. General engineering places the TEC in the "big picture" engineering plans of infrastructure in theater. Geospatial engineering collects data on the operational environment to produce a digital "map" with various levels of information to the combatant commander.

With this mission in mind, the TEC headquarters is placing all the right leaders in the right roles to fill every mission need. Much of this requires the headquarters to restructure, which they are undergoing with the help of STAFFEX.

Previously, the TEC consisted of two deployable command posts (DCP), totaling 120 Soldiers. Now they are being restructured into a single DCP of approximately 50 Soldiers. This opened up positions the TEC will fill with geospatial and more general engineering professionals.

Having an internal geospatial cell allows the TEC autonomy in supporting a combatant commander's decisions for the battlefield. The technical engineers would run the complete program of engineering across a theater.

"By creating this general engineering section (GENOC), they take this burden from us, and allow those sections to focus on their tasks and duties for the mobilization," said Kilpatrick.

Soldiers from the Geospatial Planning Cell are already seeking out digital mapping exercises with other agencies to expand their training. The GENOC has been refining its standard operating procedures (SOP) to improve workflow and efficiency. Every section has also done that, while hosting workshops, discussions and briefings. This weeklong STAFFEX has given the GENOC and other staff sections the ability to really hunker down on detail-intensive needs.

"They have really embraced this; they understand the importance of what we are doing here," said Irwin. "I have told our Soldiers at every turn how pleased and proud I am of them for the work that they have done."

These plans and hard work also affect the staff that would stay behind in case of a deployment. The Mission Support Element (MSE) would continue its day-to-day administrative requirements needed to keep the command running. In the Army Reserve, when a command headquarters deploys, none of its subordinate units deploy with it, necessarily. Those units would continue their training and peacetime missions. They would rely on the MSE for their administrative needs. Those would include everything from purchasing equipment, funding transportation for training, helping with personnel documents and more.

"When we say we are going to have a STAFFEX, how does that affect everybody?" asked Lt. Col. Jonathan Johnson, 416th TEC force development officer. "It effects both organizations inside the TEC, but it shouldn't affect the MSE as much. The MSE is doing their job Monday through Friday like they do when all of our civilians or active reserve Soldiers [AGR] are in [the office]."

The MSE is mostly formed of active reserve Soldiers and Army civilians, but it also includes a few Soldiers known as "Troop Program Unit" (TPU) who are not part of the full-time staff. These TPU Soldiers would become activated to support the MSE at their headquarters for their day-to-day functions in case of a TEC deployment. The STAFFEX has given them the opportunity to train on the systems and procedures needed to run a smooth operation.

The STAFFEX process will continue over the next two years to implement all the changes necessary. The command has scheduled exercises of increasing complexity to take place in 2016 and 2017. Within three years, the 416th TEC will be able to handle the responsibilities of a Joint Task Force Headquarters. It will be able to lead not only its Army Reserve engineer units in the United States, but strategize engineer plans anywhere in the world with the support of engineers and other services from every branch of the military.