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Leadership Team

Meet our Leaders

In 2010, Penmac Founder Patti Penny and her family transferred ownership of Penmac Staffing to the company’s employees, giving each team member a stake in the success of the company. Today, Penmac is one of the largest employee-owned staffing companies in the United States. With strong roots built by Patti Penny, the company has continued to succeed under the leadership of many talented staff. Since the beginning, Penmac has been dedicated to placing people first, as demonstrated by excellent customer service and commitment to community involvement.

Patti Penny


Patti Penny’s strong desire to help people succeed in their work led to her founding Penmac Staffing Services in 1988. In 2017, the Springfield Area Chamber of Commerce awarded Penny the Springfieldian, the Chamber’s most coveted honor, given each year to an individual who exemplifies excellence in his or her field, and dedication to improving the quality of life for the community. In 2010, Penny was honored with a Lifetime Achievement Award from the Stevie Awards for Women in Business. Penny was awarded an Honorary Doctorate in Public Affairs from Missouri State University in 2009.  In 2010, the Penny family transferred ownership of Penmac to its employees through an Employee Stock Ownership Plan. Penny stepped down as CEO in 2012, and currently serves as Chairwoman of the Board. In 2017, Patti was the sixth woman ever named Springfieldian of the Year by the Springfield Area Chamber of Commerce, given each year to an individual who exemplifies outstanding community service, excellence in his or her field and dedication to improving the quality of life for Springfield and its citizens. Her philosophy has remained the same throughout the growth of Penmac: to help people have a better life by securing work that is rewarding.

A portrait of Patti Penny - 2019
Patti Penny, founder of Penmac Staffing, chats with Caitlin Golike, director of donor services for the CFO, during a donor meeting at the CFO’s main office in Springfield. Penny has opted to donate her ownership shares of Penmac to support her charitable giving. (Photo provided by Community Foundation of the Ozarks)
portrait of Tim Massey
Penmac employees volunteering at food bank

Tim Massey


Tim Massey was named CEO of Penmac in October 2013. Massey is a 20-year veteran of the staffing industry. He most recently served as Executive Vice President of Paramount Staffing, where he managed sales and operations for the southeast United States. Massey said, “Our focus is on delivering the market’s top talent to the top employers. With over years of solid service delivery, Penmac offers unparalleled talent placement in the markets that we serve.”  In 2015, Tim was recognized with a SBJ Men of the Year award. In 2019, the Springfield Business Journal named Massey the Top Executive Officer of the year.

Paula Adams


Paula Adams joined Penmac Staffing in 1995 and worked in nearly every department before becoming Vice-President in 2002, and President in 2006. As president, Adams manages corporate and branch operations. In addition to her work with Penmac, She was named to the Staffing Industry Analysts's Staffing 100 list twice, the SIA Global Power 150 five times, and Biz 417 Magazine's Biz 100 list for the last 7 years. Adams is dedicated to improving her community, and is on the board of nine different organizations in southwest Missouri. In 2019, she was named the Springfield Business Journal's Economic Impact Community Involvement Champion.  She is a proud alumna of the University of Missouri. 

Penmac President Paula Adams
Paula Adams bellringing for Salvation Army
Penmac employees volunteering at food bank
portrait of Tim Massey

Leah Ann Iaguessa


Leah Ann Iaguessa joined Penmac as CFO in 1997. She holds a Bachelor of Science in Accounting from Arkansas State University, and is a Certified Public Accountant. Prior to joining Penmac, Iaguessa served as Corporate Accounting Controller for Mid-America Dairymen, and prior to that was a senior manager for Deloitte & Touche. Iaguessa says, “It means a lot to me to work with an organization that is very solid financially, runs the business very ethically, and gives employees flexibility and respect.” In 2015, the Springfield Business Journal named Iaguessa the Dynamic Dozen Top Local Financial Officer.

Stuart Stringer


Stuart Stringer started with Penmac in 2003, and most recently served as manager of Penmac’s largest branch office in downtown Springfield, Missouri. He was named Chief Operations Officer in December 2023. He earned a degree in Administrative Management from Missouri State University. Stringer says, “I am very thankful for the opportunity to provide the support needed to deliver the highest level of customer service to our clients and our employees. I truly believe ‘You can’t go wrong with treating people right.'”

portrait of Stuart Stringer
Penmac employees volunteering at food bank
portrait of Tim Massey

Nancy Riggs

Regional Vice-President

Shortly after receiving her Bachelors in Business Administration, Nancy Riggs joined Penmac in 1994. Riggs has worked throughout the organization in many roles, including recruiting, interviewing and screening candidates, as well as working with businesses on their hiring needs. She is a graduate of Leadership Springfield and in 2009, was named one of Springfield Business Journal’s 40 Under 40 award recipients. Riggs says, “Learning about businesses and their unique goals and needs is one of my favorite aspects of working at Penmac. I enjoy developing custom plans to help employers succeed with our HR solutions. She currently serves on the board of the Springfield Area Chamber of Commerce as Vice-Chair of Membership.

Diane Hewitt

Vice-President of Business Development

Diane Hewitt joined the Penmac team in 2020, bringing over 25 years of experience in the staffing industry including selling, managing, and servicing industrial clients. She's served accounts ranging in size from 1 to over 400 temporary employees and has been successful in negotiating and obtaining contracts with several Fortune 500 companies.

portrait of Stuart Stringer

To learn more about our area and branch managers, please visit our location pages where you will find a profile of each manager.

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