Design Operability and Retrofit Analysis (DORA) framework for energy systems

Viknesh Andiappan*, Denny K. S. Ng, Raymond R. Tan

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

27 Citations (Scopus)


A systematic framework for Design Operability and Retrofit Analysis (DORA) is presented. DORA is a framework explicitly analyzing energy system design containing process units functioning at different levels of operability. To express the operability of individual process units, DORA uses inoperability input-output modeling (IIM) approach. Based on IIM, a simple mixed integer linear programming (MILP) model is developed to analyze the impact of individual process unit inoperability on the flexibility of an energy system design. In the case where a design is deemed to possess insufficient flexibility to meet demands, DORA framework subsequently entails a step-by-step guide to debottleneck and retrofit a given design based on benefit-cost ratio (BCR). In this work, the DORA framework is demonstrated using a biomass-based tri-generation system (BTS) case study. As shown in the case study, DORA framework is used to determine whether a BTS facing a drop in individual unit efficiency, would require debottlenecking and retrofitting to increase its energy production.

Original languageEnglish
Pages (from-to)1038-1052
Number of pages15
Publication statusPublished - 1 Sept 2017


  • Design Operability and Retrofit Analysis
  • Disruption Scenario Analysis
  • Feasible operating range analysis
  • Inoperability input-output modeling, Biomass-based tri-generation

ASJC Scopus subject areas

  • Civil and Structural Engineering
  • Building and Construction
  • Pollution
  • General Energy
  • Mechanical Engineering
  • Industrial and Manufacturing Engineering
  • Electrical and Electronic Engineering


Dive into the research topics of 'Design Operability and Retrofit Analysis (DORA) framework for energy systems'. Together they form a unique fingerprint.

Cite this