---
title: "Process Control: The Passive Systems Approach"
type: source
tags: [control-theory, chemical-engineering, out-of-scope, terminological-false-friend]
authors: [Bao, Jie; Lee, Peter L.]
year: 2007
venue: "Springer-Verlag London (Advances in Industrial Control series)"
kind: book
raw_path: "raw/Process Frameworks & BPM/Process control - Bao & Lee 2007.pdf"
raw_path_duplicate: "raw/mixed/Process control - Bao & Lee 2007.pdf"
isbn: "978-1-84628-892-0"
series: "Advances in Industrial Control, ISSN 1430-9491"
created: 2026-04-20
updated: 2026-04-20
key_claims:
  - The book develops passivity-based control theory for industrial process control (robust control, decentralised control, fault-tolerant control, process controllability analysis).
  - A "process" here is a physical/chemical plant (heat exchanger, CSTR, distillation column, boiler furnace, mixing system) — not a business process.
  - Passivity is an energy-based abstraction - a passive system does not generate internal energy and is easier to stabilise via feedback.
  - The monograph is grounded in chemical/electrical engineering, systems theory, Hamiltonian mechanics and thermodynamics - not in BPM or process mining.
---

# Process Control: The Passive Systems Approach (Bao & Lee, 2007)

Engineering monograph in the **Advances in Industrial Control** series (Springer). Jie Bao (UNSW) and Peter L. Lee (University of South Australia). 7 chapters plus references; focused on **passivity-based control** for industrial processes.

## Why it is (only marginally) relevant here

**This book is a terminological false friend.** The word "process" in its title refers to **physical/chemical processes** — heat exchangers, continuous stirred-tank reactors, distillation columns, boiler furnaces — not to business processes. The "control" refers to **feedback control theory** (stabilisation of dynamical systems), not to BPM process control, compliance, or conformance.

It appears in `raw/Process Frameworks & BPM/` because a filename-based literature collection swept it in alongside genuine BPM books. Keeping a short source page is worthwhile for three reasons:

1. **Lint hygiene** — so future searches on "process control" land on this disambiguation instead of silently conflating three traditions.
2. **Terminological disambiguation** — the word "process control" in BPM / OM / chemical engineering denotes three distinct things:
   - **Chemical-engineering process control** (this book): feedback stabilisation of plant dynamics via passivity / H∞ / model-predictive control.
   - **Statistical Process Control** (SPC, OM tradition — see [[sources/2007-slack-operations-management]] Ch. 17): control charts, process capability, acceptance sampling, upper/lower control limits on a measured variable.
   - **BPM process control / conformance** ([[concepts/conformance-checking]]; [[sources/2011-vanderaalst-process-mining-book]] Ch. 8): detecting deviations of event-log behaviour from a prescribed process model.
3. **Possible far-future bridge** — concepts like **controllability** (Ch. 6) and **fault tolerance** (Ch. 5) have analogues in self-adaptive / agentic BPM (e.g., [[concepts/mape-k-loop]] is partly descended from control theory). Any serious agentic-BPM-meets-control-theory work would need to consult this tradition, but the current wiki does not require it.

## Ingest strategy

Minimal-sufficient. No deep-dive planned. Flagged `out-of-scope` in tags.

## Book structure

| Ch | Title | Content |
|---|---|---|
| 1 | Introduction | Motivation for passive-systems approach |
| 2 | Dissipativity and Passivity | Foundations: passive systems, KYP property, phase, interconnection, passivity indices, passivation, passivity theorem |
| 3 | Passivity-based Robust Control | Uncertainty characterisation; robust stability + nominal performance; combining with small-gain; CSTR and mixing examples |
| 4 | Passivity-based Decentralised Control | Decentralised integral controllability; BDIC; dynamic interaction measure; boiler furnace case |
| 5 | Passivity-based Fault-tolerant Control | Sensor/actuator fault representation; DUS condition; PI control; stable + unstable processes |
| 6 | Process Controllability Analysis Based on Passivity | Extended internal model control; regions of attainability; high-purity distillation column case |
| 7 | Process Control Based on Physically Inherent Passivity | (Guest chapter by Hangos & Szederkényi) thermodynamics, Hamiltonian systems, physical-passivity foundations |

## Connections

Primarily **negative connections** — this is what to *not* conflate with when a BPM source says "process control":

- Not related to [[concepts/conformance-checking]] (BPM sense).
- Not related to SPC in [[sources/2007-slack-operations-management]].
- Not related to operational support / [[concepts/operational-support]] in [[sources/2011-vanderaalst-process-mining-book]].

**Weak positive connection:** MAPE-K ([[concepts/mape-k-loop]]) and self-adaptive control loops share ancestry with feedback-control theory as represented here, but the engineering-control literature is a parallel universe to the MAPE-K / IBM Autonomic Computing line typically cited in BPM.

## Open questions
- If any future wiki page needs to draw the three-way distinction between chemical-process control, statistical process control, and BPM conformance, this page should be the landing point.