Aspen PIMS: Advanced Optimization Features

Course Id:  RPA221   |   Duration:  2.00 day(s)   |   CEUs Awarded:  1.4   |   Level:  Intermediate

Course Objective

Learn the differences between standard Aspen PIMS using Distributed Recursion and Aspen PIMS Advanced Optimization using the XNLP framework. Learn to troubleshoot suboptimal solutions inherent to non-linear optimization problems.

Course Overview

  • Provides an in-depth exploration of the capabilities of Aspen PIMS Advanced Optimization
  • How-to training on Advanced Optimization Analysis, including Parametric Programming, Ranging Analysis, Goal Programming, and Feedstock Basket Reduction


  • Review limitations of Distributed Recursion modeling framework and motivations for introducing Advanced Optimization
  • Gain familiarity with the XNLP and XSLP technologies
  • Use Advanced Optimization Analysis tools to evaluate deviations from optimal solution
  • Execute different Global Optimization procedures
  • Add and edit non-linear formulas to model
  • Attach external models, use them for simulation and optimization
  • Set Up and run High Performance Computing architecture


Participants will typically know how to use Aspen PIMS and want to take advantage of the expanded capabilities of the Aspen PIMS Advanced Optimization software.


  • Class lectures describe the differences between standard Aspen PIMS using Distributed Recursion and Aspen PIMS Advanced Optimization using the XNLP framework, and focus on the use of the new functionality
  • The features of Aspen PIMS Advanced Optimization are thoroughly described in lectures and demonstrations
  • Class problems are designed to familiarize the student with the features of Aspen PIMS Advanced Optimization. Time is allotted to allow the student to explore these features¬†


Must have attended RPA101 Aspen PIMS: Introduction to Refinery Planning.

Class Schedule

Class Agenda

RPA221: Aspen PIMS: Advanced Optimization Features

Introduction to Aspen PIMS Advanced Optimization

  • Describe the limitations of the existing modeling and solution framework (DR)
  • Discuss some of the solutions to these limitations
  • List the advantages of moving to PIMS-AO

Migrating a PIMS Model to PIMS-AO
  • Review the DR model looking for any indications of poor model structure
  • Discuss DR warning messages that indicate a potential problem
  • Ensure DR model is running well and producing a good solution
  • Switch to PIMS-AO and review any new messages
  • Develop a generalized input solution to initialize PIMS-AO
  • Review recommended model settings

Global Optimization
  • Identify local optima problem
  • Compare global optimization techniques in Distributive Recursion and Advanced Optimization
  • Apply different Global Optimization techniques in Advanced Optimization
  • Workshop: Working with Local Optima in DR and PIMS-AO

Advanced Optimization Analysis
  • Identify solution analysis methods available in Distributive Recursion and Advanced Optimization
  • Apply correct solution analysis technique to corresponding type of problem
  • Set up Advanced Optimization Analysis
  • Evaluate results of Advanced Optimization Analysis
  • Workshop: Parametric Analysis
  • Workshop: Goal Programming
  • Workshop: Ranging Analysis
  • Workshop: FeedStock Basket Reduction

Modeling and Solution Technology: XNLP and XSLP
  • Differentiate key aspects of Distributive Recursion vs. XNLP
  • Apply the different Initialization methods to start a run in XNLP
  • Identify XSLP linearized structure and key convergence parameters
  • Track linear and nonlinear model equations using Matrix Analyzer and PIMS-AO Execution Report
  • Access key XNLP and XSLP settings
  • Gain familiarity with main issues when converting from Distributive Recursion to XNLP
  • Workshop: Initialization Methods in XNLP-
  • Workshop: Model diagnostics and infeasibility troubleshooting in PIMS-AO.

High Performance Computing
  • Use new XLP Matrix Generator functionality
  • Use Parallel Processor architecture for running multiple cases and Global Optimization Multistart for the flowsheet

Nonlinear Formulation
  • Identify main sources of nonlinearities in models
  • Differentiate non-linear modeling tools in Distributive Recursion and Advanced Optimization
  • Add and edit non-linear formulas
  • Connect external non-linear models to a PIMS model
  • Use external models for optimization and/or for simulation
  • Workshop: Throughput Dependent Yields
  • Workshop: Quality Cross Product
  • Workshop: Feed Dependent Utility
  • Workshop: Using An External Model

Aspen Technology, Inc. awards Continuing Education Units (CEUs) for training classes conducted by our organization. One CEU is granted for every 10 hours of class participation.