Thomas J. Harris, P.Eng.


Tel: (613) 533-6771
Fax: (613) 533-6637
Email: or
Office: Dupuis Hall


Research Interests

  • Process Control
  • Process Monitoring and Controller Performance Assessment
  • Statistical Methods in Chemical Engineering

Professor Harris' activities are directed towards the analysis of process control strategies and the development and use of statistical methodologies in chemical engineering. Current projects include the use of nonparametric and parametric statistical methods for structural and performance analysis, development of performance analysis tools to account for process nonlinearities and the use of generalized profiling and Markov Chain Monte Carlo (MCMC) methods to provide meaningful uncertainty analysis of process models that are used for control and analysis purposes.


NSERC Discovery, Novelis, MITACS, OCE



Journal Publications

Wu, S., McLean, K., Harris, T.J., and K.B. McAuley, "Selection of Optimal Parameter Set Using Estimability Analysis and MSE-based Model-Selection Criterion ," International Journal of Advanced Mechatronic Systems 2011 [More information].  (Accepted)

Harris, T.J. and Wei-Yu, "Variance decompositions of nonlinear time series using stochastic simulation and sensitivity analysis,"Statistics and Computing 2011 [More information].  (Accepted)

Wu,S., McAuley,K.B., and Harris. T.J., "Selection of Simplified Models: II. Development of a Model Selection Criterion Based on Mean-Squared-Error," 89, 2, 325-336, 2011.

Wu,S., McAuley, K.B. and T.J. Harris, "Selection of Simplified Models: I. Analysis of Model Selection Criteria using Mean-Squared Error," Canadian Journal of Chemical Engineering 89, 1, 148-158, 2011 [More information].

Harris, T.J. and Hui Yuan, "Filtering and frequency interpretations of Singular Spectrum Analysis ," Physica D: Nonlinear Phenomena 239, 1958-1967, 2010 [More information].

Harris, T.J. and Wei-Yu, "Variance decompositions of nonlinear-dynamic stochastic systems," Journal of Process Control 20, 195-205, 2010 [More information].

T.J. Harris, "Interpretations of Multivariate Performance Indices," Journal of Process Control 19, 701-710, 2009 [More information].

Wei-Yu, Harris, T.J., "Parameter Uncertainty Effects on Variance-based Sensitivity Analysis," Reliability Engineering and Systems Safety 94, 596-603 , 2009 [More information].

Wu, Shaohau, Harris, T.J., McAuley, K.B., "The Use of Simplified or Misspecified Models: Linear Case," Canadian Journal of Chemical Engineering 85, 4, 386-398, 2007 [More information].

Harris, T.J. and Wei-Yu, "Controller Assessment for a Class of Nonlinear Systems," Journal of Process Control 17, 607-619, 2007[More information].

Quinn, S.L., Harris, T.J. and D.W. Bacon, "Measuring Uncertainty in Control-Relevant Statistics," Journal of Process Control 15, 675-690, 2005 [More information].

T.J. Harris, "Statistical Properties of Quadratic-Type Performance Indices," Journal of Process Control 14, 899-914, 2004 [More information].

Harris,T.J., Wei-Yu, "Analysis of Multivariable Controllers Using Degree of Freedom Data," International Journal of Adaptive Control and Signal Processing 17, 569-588, 2003 [More information].

Seppala,C.T., Harris, T.J., and D.W. Bacon, "Time Series Methods for Dynamic Analysis of Multiple Controlled Variables," Journal of Process Control 12, 257-276, 2002 [More information].

Quinn, S.L., Bacon, D.W., and T.J. Harris, "Notes on Likelihood Intervals and Profiling," Communications in Statistics 29, 108-130, 2000 [More information].

Quinn, S.L., Bacon, D.W., and T.J. Harris, "Using Generalized Profiling to Estimate Likelihood Intervals for Model Predictions and Other Functions of Model Parameters," Canadian Journal of Chemical Engineering 77, 723-737, 1999 [More information].

Harris, T.J., Seppala, C.T., and L.D. Desborough, "A Review of Performance Monitoring and Assessment Techniques for Univariate and Multivariate Control Systems," Journal of Process Control 9, 1-17, 1999 [More information].

Toffolo, R.W., Harris,T.J., and J.H. Davis, "Numerical Inversion of Characteristic Equations with Applications to Quadratic Forms in Normal Variables," Communications in Statistics: Simulation and Computation 27, 215-228, 1998 [More information].

Harris, T.J., Seppala, C.T., Jofriet, P.J., and B.W. Surgenor, "Plant-Wide Feedback Control Performance Assessment Using an Expert-system Framework," Control Eng. Practice 4, 1297-1303, 1996 [More information].

Jofriet, P., Seppala, C., Surgenor, B. and T. J. Harris, "An Expert system For Control Loop Performance," Pulp & Paper Canada 97, 207-211, 1996 [More information].

Harris, T.J., Boudreau, T., and J.F. MacGregor, "Performance Assessment of Multivariable Feedback Controllers," Automatica 32, 1505-1518, 1996 [More information].

Piette, R., Harris, T.J., and P.J. McLellan, "Graphical Interpretation of Steady State Interaction Measures," Industrial & Engineering Chemistry Research 34, 4436-4450, 1995 [More information].

Desborough, L.D. and T.J. Harris, "Performance Assessment Measures for Univariate Feedforward/Feedback Control," Canadian Journal of Chemical Engineering 71, 605-818, 1993 [More information].

Desborough, L.D. and T.J. Harris, "Performance Assessment Measures for Univariate Feedback Control," Canadian Journal of Chemical Engineering 70, 1186-1197, 1992 [More information].

Harris, T.J. and W.H. Ross, "Statistical Process Control Procedures for Correlated Observations," Canadian Journal of Chemical Engineering 69, 48-57, 1991 [More information].

Harris, T.J., "Assessment of Control Loop Performance," Canadian Journal of Chemical Engineering 67, 856-861, 1989 [More information].


Harris, T.J., "Liquid Phase Preparation of (meth)-Acrylate," U.S. Patent 5670702, September, 1997.

Conference Proceedings

Wei-Yu, Wilson, D., Young, B. and Harris, T.J., "Variance Decompositions of Nonlinear Systems," 7th IEEE International Conference on Control & Automation , Christchurch, New Zealand, December, 2009, [More information].  (Accepted)

Harris, T.J. and C.T. Seppala, "Recent Developments in Controller Performance Monitoring and Assessment Techniques," Chemical Process Control VI, pp. 208-222, Vol. 98, Tuscon, AZ, January, 2001, [More information].

Harris, T.J., Seppala, C.T., and D.W. Bacon, "Dynamic Analysis of Variance Methods for Multivariate Control System Data," 1st International Symposium on Industrial Statistics (Understanding Varation: A Key to Successful Quality Improvement), Link?ping, Sweden, August, 1999, [More information].

Conference Presentations

"An Analysis of Model Selection Criteria (MSC) in the Case of Underfitting," MITACS 2009, Fredericton, NB, June, 2009. [More information].

"Inference in Nonlinear Regression: Progress and Challenges," Dept of Statistics, University of Toronto, January, 2007. [More information].

"Not So Simple! Analyzing Simplified & Misspecified Models," 57th Canadian Chemical Engineering Conference, Edmonton, Alberta, 2007. Keynote Presentation, [More information].

"Interpretations and Analysis of Performance Bounds for Multivariable Systems," 55th Canadian Chemical Engineering Conference, Toronto, ON, October, 2005. D.G. Fisher Award Lecture, [More information].

"Parameter Uncertainty Effects on Input Sensitivity Analysis," 54th Canadian Chemical Engineering Conference, Calgary, AB, October, 2004. Paper 250, [More information].

"Observations and Thoughts on Controller Assessment and Performance Monitoring," Control Systems 2004, Quebec City, QC, June, 2004. [More information].

"Assessing Parameter Uncertainty Using Markov Chain Monte Carlo Methods," 53rd Canadian Chemical Engineering Conference, Hamilton, ON, October, 2003. Paper 273, [More information].

"When Simplified Models are Better than the True Model," 55th Canadian Chemical Engineering Conference, Toronto, ON, 2002.[More information].

"Estimating Model Uncertainty Using Model Error Modelling," 52nd Canadian Chemical Engineering Conference, Vancouver, B.C., October, 2002. [More information].

"Analysis of Multivariable Controllers Using Markov Chains," 52nd Canadian Chemical Engineering Conference, Vancouver, B.C., October, 2002. [More information].

"Estimation of Co-Integrated Relationships in Process Data," 50th Canadian Chemical Engineering Conference, Montreal, QC, October, 2000. Paper W73E, [More information].

Theses Supervised

Variance Analysis for Nonlinear Systems, 2007.  (In Progress)

Wu,S., Two-Step Estimation in Linear Regression (co-supervised with K.B. McAuley), M.Sc. thesis, 2005.

Soon, A., A Generalized Profiling Approach to Inference Analysis in System Identification (co-supervised with P.J. McLellan), M.Sc. thesis, 2005.

Breck, Colin S., Fault Detection For an Aircraft Environment Control System Using Dynamic Principal Component Analysis, (co-supervised with P.J. McLellan), M.Sc. thesis, 2005.

Uche, Ikenna, An Analysis of Model Error Modelling, M.Sc. thesis, 2003.

Wei-Yu, Applications of Time Series Count Data for Process Analysis, M.Sc. thesis, 2002.

Liew, Chen Nei, Estimation of Cointegrating Relationships in Process Data, M.Sc. thesis, 2002.

Patton, M., Describing Uncertainty in State Estimates (co-supervised with P.J. McLellan), M.Sc. thesis, 2000.

Seppala, C.T., Dynamic Analysis of Variance Methods for Monitoring Control System Performance, (co-supervised with D.W. Bacon), Ph.D. thesis, 1999.

Quinn, S.L., Measuring and Predicting Uncertainty in Control-Relevant Statistics, Ph.D. thesis, (co-supervised with D.W. Bacon), 1999.

Laflamme, J., Dynamic model of the solid state polymerization of nylon 6,6, (co-supervised with P.J. McLellan), M.Sc. thesis, 1997.

Neagu, L. (M.Sc.) Production of BHP by Catalytic Distillation, (co-supervised with B.W. Jackson), M.Sc. thesis, 1997.

Logan., G.A., Synthesis of dimethyl carbonate with CuC12 , (co-supervised with B.W. Jackson), M.Sc. thesis, 1997.

Zagrobelny, J., System Identification Techniques for a Rolling Mill Gauge System, (co-supervised with M. Bayoumi), M.Sc. thesis, 1996.

Rose, J., Reactive Distillation, (co-supervised with B. Jackson), M.Sc. thesis, 1994.

Piette, R., Geometric Interpretation of Interaction Measures, (co-supervised with P.J. McLellan), M.Sc. thesis, 1994.

Berg, David, Mass Transfer Resistances in MTBE Synthesis, Ph.D. thesis, 1994.

Baumert, R.M., Performance Modelling of the Ballard Mark IV Solid Polymer Electrolyte Fuel Cell, (co-supervised with R.F. Mann, RMC), M.Sc. thesis, 1993.

Foley, Michael, H-infinity Methods for Chemical Process Control, Ph.D. thesis, 1993.

Peppley, B., Catalytic Steam Reforming of Methanol Using a Commercial Low Temperature Shift Catalyst, (co-supervised with R.F. Mann, RMC), M.Sc. thesis, 1993.

Kuye, M.A., An Evaluation of Microbial Biomass Estimation Techniques in Dynamic Fermentation Processes and Their Impact on Modelling, (co-supervised with A.J. Daugulis), M.Sc. thesis, 1992.

Desborough, L., Performance Assessment Measures for Univariate Control, M.Sc. thesis, 1992.

McLellan, P.J., Nonlinear Error Trajectory Controllers for Output Tracking and Disturbance Rejection, (co-supervised with D.W. Bacon), Ph.D. thesis, 1990.

Yuet, P.K., Mathematical Modelling of Animal Cell Growth in Micocapsules, (co-supervised with M.F.A. Goosen), M.Sc. thesis, 1990.