PhD Program
PhD Admissions
Admission Criteria & Background

The Department of Industrial Engineering and Management Sciences has a high standard for PhD admissions. This page serves as a guide so that you can see how you compare to our typical admitted applicant.

Please note that not meeting one of these criteria will not prevent you from being considered for admission. We review each application as a whole, and an applicant’s strength in one area can compensate for a weakness in another. We do not provide preliminary evaluations for prospective students.

Evaluation Criteria

Successful applicants often have many of the following characteristics:

  • GRE-Quantitative score above 160 under the new scoring system or 760 under the old scoring system.
  • GRE-Analytical Writing score of 4.0 (41st percentile) or higher is desirable. A score of 3.0 (10th percentile) is poor. This test plays a role in admissions because students in the program need to write research papers and dissertations.
  • Although the major field test in mathematics offered by ETS is not required, a good score on this test will be viewed very favorably.
  • If applicable, a score of at least 90 on the internet-based TOEFL, 600 on the paper-based TOEFL, or 7.0 on the IELTS. This is a minimum requirement and no exceptions will be made.

Academic Record

Admissions into the PhD program requires applicants to have a good academic record from a top-tier college or graduate program. It is difficult to give precise guidance about what this means because the grading schemes, curricula, and selectivity of different colleges vary greatly.

We concentrate on the following characteristics:

  • Grades in mathematics, industrial engineering, and computer science are most important.
  • At a top-tier institution, a grade point average of at least 3.7 out of 4.0 or 90 out of 100 is desirable.
  • Most of our students were in the top 2% - 10% of their classes at top-tier institutions.

Research Experience

Many successful applicants did not have substantial research experience, but most of them were able to demonstrate their potential for research with letters of recommendation.

Letters of recommendation

The Department of Industrial Engineering and Management Sciences prefers letters of recommendation that attest to the applicant's potential to grow into an independent researcher and suitability for mathematically challenging PhD coursework.

Learn more about submitting letters of recommendation.

Statement of Purpose

The Department of Industrial Engineering and Management Sciences prefers a statement of purpose that demonstrates that the applicant has goals that can be met by completing our PhD program.

Learn more about submitting a statement of purpose.

Language Requirement

Students need to have the ability to write and speak English well.

Required Standardized Tests

Graduate Record Examination

All applications must be accompanied by scores on the Graduate Record Examination (GRE) aptitude test. Official scores must be taken no more than five years before the intended quarter of entry and must come directly from the Educational Testing Service (ETS).

For example, to be considered valid for Fall 2017 admission, GRE scores must be no older than September 1, 2012. Personal copies are not considered official, nor are "attested" or notarized copies. If you have not already taken the GRE, it is best to take the test three to four months before the application deadline.


For international applicants whose native language is not English, evidence of ability in English must be demonstrated by achieving a minimum score of 90 on the internet-based TOEFL, 600 on the paper-based TOEFL, or 7.0 on the IELTS. Applications with scores lower than those listed above will not be considered. There are no exceptions. 

Official scores mst be taken no more than two years before the intended quarter of entry.  For example, to be considered valid for Fall 2017 admission, TOEFL scores must be no older than September 2015. 

This exam requirement is waived only if you will have received, before matriculation, a degree from a university whose language of instruction is English. Be sure to take all needed tests in time for official scores to reach The Graduate School by the application and financial award deadline (December 15). Usually, this means taking an examination at least three months before the given application deadline.

Score Reporting for GRE and TOEFL

The institutional code assigned to The Graduate School at Northwestern by ETS is 1565. If you are taking the TOEFL or GRE be sure to include this number on your test form. If your results are not sent to this code, we will not receive them. Official reports must be received before a student can be admitted.

Students taking the paper-based TOEFL should reference department code 01. This will ensure that the TOEFL scores are sent to The Graduate School and not to the undergraduate college.

TOEFL Internet-based test takers should, when prompted, request that their scores be sent to the graduate office (not the undergraduate office), and then select the program name that most closely matches their program of interest. If no match is available, the test taker may choose option 99.

The Admissions Handbook has all the information you will need, including requirements, application checklist, and frequently asked questions.