Doctoral program · Rossin College
PhD in Industrial and Systems Engineering
The PhD in Industrial and Systems Engineering at Lehigh University’s P.C. Rossin College of Engineering and Applied Science builds deep proficiency in the field and the capacity for independent research, shown through a dissertation, for students headed to teaching, consulting or research roles in academia, government or industry.
- Degree awardedDoctor of Philosophy in Industrial and Systems Engineering
- DepartmentIndustrial and Systems Engineering
- Typical time to degree4 to 5 years
- Credit hours72 minimum
- Fall deadlineDecember 15
- GRENeither accepted nor reviewed
- Application fee$50 USD
Overview
What the PhD in Industrial and Systems Engineering is
The program is organized around each student’s own goals and interests, and it is comprehensive in scope for anyone who wants to work at the cutting edge of the discipline. Every student builds a shared base in research methods, optimization, and probability and stochastic processes, then deepens it with technical electives chosen for the research ahead.
A vibrant perspective on the next generation of data science runs through the curriculum. Students gain the knowledge base and research skills needed to mine and analyze high-volume data using state-of-the-art optimization and stochastic modeling techniques.
The Department of Industrial and Systems Engineering maintains the authoritative program detail. See the department page.
Research
Research directions
Faculty and doctoral students in the department take on large, complex problems in which good decisions depend on huge amounts of data and incomplete information: planning and operating complex systems, choosing well under uncertainty, learning from high-volume data, and putting emerging computing technology to work.
Optimization Methods and Computing
Optimization underlies how organizations plan, allocate and schedule. Research in this area develops the theory and algorithms behind convex, conic, continuous and discrete optimization, and extends them to new computing platforms, including quantum computing.
Focus topics: Mathematical optimization, Quantum computing optimization.
Uncertainty and Stochastic Systems
Real systems face randomness, incomplete information and many interacting parts. This work builds stochastic models, methods for optimization under uncertainty, and tools for quantifying how uncertainty spreads through a complex system, so that decisions hold up when conditions change.
Focus topics: Stochastic models and optimization, Uncertainty quantification and complex systems.
Data and Operations
Modern organizations collect far more data than they can act on unaided. Researchers here combine optimization and stochastic modeling with machine learning to mine and analyze that data, and apply operations research to networks, supply chains and other operating systems.
Focus topics: Data science and machine learning, Applied operations research.
Research groups and programs
Lehigh ISE FACET Program
Future Academic Career Experiential Training.
Degree requirements
What the doctorate requires
A minimum of 72 credits beyond a prior bachelor’s degree, or a minimum of 48 credits with a prior technical master’s degree obtained at another institution. Lehigh publishes the following complete set of requirements.
- Credit hours
A minimum of 72 credits beyond a prior bachelor’s degree, or a minimum of 48 credits if a prior technical master’s degree has been obtained at another institution. Credits beyond coursework are earned for research through dissertation credits or maintenance of candidacy credits. No course graded below C- counts toward the degree.
- Required core courses
All students take ISE 403 Research Methods, ISE 406 Fundamentals of Optimization, and ISE 429 Probability and Stochastic Processes, 3 credits each.
- Technical electives
Six courses at the 400 level, at least five of which come from this list of ISE courses: ISE 401 Convex Analysis, ISE 402 Operations Research Models and Applications, ISE 407 Numerical Methods and Scientific Computing, ISE 411 Networks and Graphs, ISE 412 Quantitative Models of Supply Chain Management, ISE 414 Uncertainty Quantification, ISE 415 Optimization Under Uncertainty, ISE 416 Dynamic Programming, ISE 417 Continuous Optimization, ISE 418 Discrete Optimization, ISE 422 Quantum Computing Optimization, ISE 444 Optimization Methods in Machine Learning, and ISE 456 Conic Optimization. One course may be taken outside of ISE.
- Dissertation credits
ISE 499 Dissertation, 1 to 9 credits, is repeatable without limit through admission to candidacy.
- Courses that do not count
Courses with an ESLP or EAPC subject code, undergraduate-only 300-level courses such as ISE 300 Apprentice Teaching, ENGR 492 Summer Research and ENGR 496 Summer Work Experience cannot be counted toward the degree.
- Advisor
Acquire an advisor from among the program faculty members.
- Qualifying exam
A research-based exam given from late spring to early fall after the first year in the program, to evaluate progress in independent research and critical thinking. It consists of a research report reviewed by a committee of faculty members and an oral presentation to the committee. Students receive a pass or fail determination with constructive feedback, and a student who fails has the chance to retake the exam the next year.
- Reviews
Pass a Performance Review conducted by the program faculty and a Program Review conducted by the ISE Director of Graduate Studies. Annual progress reports are submitted to the Director of Graduate Studies.
- Doctoral committee
Form a doctoral committee satisfying the Rossin College requirements.
- Defense of the research plan
A written document describing the planned research projects must be defended in an oral presentation before the dissertation committee. The defense typically occurs in the second or third year in the program. Students receive a pass or fail determination with constructive feedback, and a student who fails has the chance to present the plan again.
- General exam
The general exam is passed if and only if the student passes the defense of the research plan.
- Admission to candidacy
The Rossin College sets the requirements for admission to candidacy.
- Dissertation and defense
Prepare a dissertation related to your field of specialization and defend it before the doctoral committee. A dissertation is required for the PhD program.
- Language
The program has no in-program language requirements.
Year by year
| Year | Milestone |
|---|---|
| After the first year | Qualifying exam, given from late spring to early fall. |
| Second or third year | Defense of the research plan before the dissertation committee, which also serves as the general exam. |
Curriculum
Core and required courses
| Code | Course | Focus |
|---|---|---|
| ISE 406 | Fundamentals of Optimization | Linear, discrete, and convex optimization. |
| ISE 429 | Probability and Stochastic Processes | Probability and stochastic processes for models. |
Careers
Where graduates work
Industrial and systems engineering alumni apply optimization, modeling and data skills across technology, finance, life sciences and education.
Doctoral-level training in optimization, stochastic modeling and data science leads to faculty positions, research and development roles, and technical leadership in industry. Alumni titles include assistant, associate and adjunct professor, applied scientist, machine learning engineer, lead data scientist and data science manager, and many alumni move into senior management and executive roles. They work in information technology, finance, life sciences, education, manufacturing, consulting and healthcare.
Employers where our alumni most often work include:
- Amazon
- Meta
- Axtria
- EY
- JPMorgan Chase
- Johnson & Johnson
- Deloitte
Alumni also work at Air Products, KMK Consulting, Citi, Greenwich Biosciences, Intel, SAS and TikTok.
Based on current employers of Lehigh industrial and systems engineering alumni, all degree levels, who graduated between 1996 and 2025.
Funding
Financial support
All PhDs at the Rossin College are 100% fully-funded, however, funding sources may vary by department. Funding covers PhD tuition and a stipend.
Admitted students are guaranteed financial support for the entire duration of the program (subject to successful performance).
- PhD applicants wishing to be considered for financial assistance should submit a complete application no later than December 15 for a fall semester start.
- Named opportunities open to Rossin College doctoral students include the Rossin Research Scholars program, Pasteur PhD Partners (P3), and the SEED-EF NSF National Research Traineeship, see special opportunities for Lehigh PhD students.
- Financial aid for Lehigh’s graduate programs consists mainly of fixed-rate federal student loans through the Office of Financial Aid.
- Loan eligibility requires enrollment at least half-time, six credits during the academic year, three credits in summer.
- Emergency loans and grants are available through the Graduate Life Office.
Admissions
How to apply
Applications for admission, all semesters, all levels, are completed online. Applications open September 1; PhD applications for fall admission are due December 15 for financial aid consideration.
Application open dates and deadlines are determined by individual departments. Contact the department concerning relevant deadlines and available start terms.
What to submit
- Completed online application
- Official transcripts (with English translation for international applicants)
- Statement of purpose / essay
- Letters of recommendation (typically three)
- Résumé or CV
- Application fee of $50 USD
Industrial and Systems Engineering requirements
- Prior degree: A strong background in industrial engineering, mathematics, computer science, or a similar discipline is required.
- GPA: A GPA of 2.75 or equivalent. Universities outside the United States have different grading scales and averages, and the program considers only high-performing students in their respective programs.
- Deadline: The annual deadline for applications is December 15.
GRE scores are neither accepted nor reviewed for any Rossin College graduate program.
English proficiency minimums
| Test | Minimum score |
|---|---|
| TOEFL iBT | Overall 81 (old scale) / 4 (new scale); Speaking 22/4, Writing 20/4, Reading 20/4, Listening 16/4 |
| IELTS | Overall 6.5; Speaking 6.5, Writing 6, Reading 6.5, Listening 6 |
| Duolingo English Test | Overall 125; Speaking 125, Writing 120, Reading 125, Listening 110 |
| Cambridge | Overall 176; Speaking 176, Writing 169, Reading 176, Listening 169 |
| Pearson (PTE) | Overall 68, with 53 or higher on each band |
Scores expire two years from the test date. MyBestScore and One Skill Retake formats are not accepted. Waivers are available for applicants who are citizens or permanent residents of an English-speaking country, earned a U.S. degree with two or more years of in-person study, earned a degree taught in English in an English-speaking country, or studied or worked full-time in an English-speaking country for two or more years within the last five.
Questions
Frequently asked questions
Which department at Lehigh offers the PhD in Industrial and Systems Engineering?
The PhD in Industrial and Systems Engineering is offered by Lehigh University’s Department of Industrial and Systems Engineering, within the P.C. Rossin College of Engineering and Applied Science. Full program detail, faculty and current requirements are maintained on the department’s own page: https://engineering.lehigh.edu/ise/academics/phd
Who is the PhD in Industrial and Systems Engineering designed for?
It is designed for students whose plans include teaching, consulting or research in an educational, governmental or industrial environment. Each candidate shows a high level of proficiency in one or more fields of industrial and systems engineering and a capacity for independent research through a dissertation in a field of specialization.
How long does the PhD in Industrial and Systems Engineering take?
4 to 5 years. The qualifying exam comes after the first year, and the defense of the research plan typically occurs in the second or third year.
How many credits does the PhD in Industrial and Systems Engineering require?
A minimum of 72 credits beyond a prior bachelor’s degree, or a minimum of 48 credits with a prior technical master’s degree obtained at another institution.
Do I need a master’s degree to apply?
No. Students enter with either a bachelor’s degree or a prior technical master’s degree from another institution. The credit requirement differs: a minimum of 72 credits beyond a bachelor’s degree, or a minimum of 48 credits with the prior master’s degree.
What background and GPA does the program expect?
A strong background in industrial engineering, mathematics, computer science or a similar discipline is required. The program looks for a GPA of 2.75 or equivalent. Universities outside the United States have different grading scales and averages, and the program considers only high-performing students in their respective programs.
Is the GRE required for the PhD in Industrial and Systems Engineering?
No. GRE scores are neither accepted nor reviewed for any P.C. Rossin College of Engineering and Applied Science graduate program.
What is the application deadline for the PhD in Industrial and Systems Engineering?
The annual deadline for applications is December 15. At the college level, PhD applications for fall admission are due December 15 for financial aid consideration, and applications open September 1. Application open dates and deadlines are determined by individual departments. Contact the department concerning relevant deadlines and available start terms.
Is the PhD in Industrial and Systems Engineering funded?
All PhDs at the Rossin College are 100% fully-funded, however, funding sources may vary by department. Admitted students are guaranteed financial support for the entire duration of the program (subject to successful performance).
What courses do PhD students take?
Everyone completes ISE 403 Research Methods, ISE 406 Fundamentals of Optimization and ISE 429 Probability and Stochastic Processes. Students then take six technical electives at the 400 level, at least five from a list of ISE courses in areas such as convex, conic, continuous and discrete optimization, uncertainty quantification, dynamic programming, networks and graphs, supply chain models, quantum computing optimization and optimization methods in machine learning. One elective may be taken outside of ISE. The remaining credits come from dissertation research.
What is the qualifying exam?
It is a research-based exam given from late spring to early fall after the first year in the program. You submit a research report that a committee of faculty members reviews, then give an oral presentation to the committee. You receive a pass or fail determination with constructive feedback, and you can retake the exam the next year if you do not pass.
What milestones follow the qualifying exam?
You defend a written description of your planned research before a dissertation committee, typically in the second or third year. Passing that defense also passes the general exam. You are then admitted to candidacy under Rossin College requirements, complete your research, and defend your dissertation.
Is a foreign language required?
No. The program has no in-program language requirements.
What research areas can I work in as a PhD in Industrial and Systems Engineering student?
Research directions published by the Department of Industrial and Systems Engineering: Optimization Methods and Computing; Uncertainty and Stochastic Systems; Data and Operations.
Who do I contact about the PhD in Industrial and Systems Engineering?
Joyce Gabay, jlg222@lehigh.edu is the graduate contact for the Department of Industrial and Systems Engineering. The department can be reached at ise@lehigh.edu or (610) 758-4050. General Rossin College graduate inquiries go to engineering@lehigh.edu.
What courses do students take in the PhD in Industrial and Systems Engineering?
Required courses include Fundamentals of Optimization, and Probability and Stochastic Processes. Other courses students can choose from include Convex Analysis, Operations Research Models and Applications, Numerical Methods and Scientific Computing, Networks and Graphs, Uncertainty Quantification, and Continuous Optimization, among others. Coursework is planned with your advisor and doctoral committee, and the Lehigh course catalog carries the current requirements.
Contact
Talk to the department
Department of Industrial and Systems Engineering
Graduate contact
Joyce Gabay · jlg222@lehigh.edu
Address
Harold S. Mohler Laboratory
200 West Packer Avenue
Bethlehem, PA 18015-1582
Phone and email
(610) 758-4050
ise@lehigh.edu
P.C. Rossin College of Engineering and Applied Science
19 Memorial Drive West
Bethlehem, PA 18015
engineering@lehigh.edu
More from the department
- Industrial and Systems Engineering PhD program
- Department of Industrial and Systems Engineering
- ISE PhD Program Quick Guide (PDF)
- ISE PhD Program Rules and Procedures (PDF)
- ISE research directions
- Meet an ISE graduate student
- Industrial and Systems Engineering (ISE) Course Listing
- Rossin College Graduate Student Handbook