Milestone map
Milestone map
3 milestones
Select Process and Establish PFD Scope
1 week (2–3 hrs/week)
Choose a chemical or industrial process to document — a distillation unit, reactor system, utility package, or similar. Establish the PFD scope: which unit operations and streams are included, what the system boundary is. Plan the PFD structure: how many unit operations, how streams will flow left-to-right, and which streams need heat and material (H&M) balance data. A well-planned scope prevents the most common PFD error: missing streams or equipment that makes the balance tables inconsistent.
Proof required
Submit your PFD scope document: the process selected, a written description of what is included and excluded, a sketch of the planned PFD layout (hand-drawn is acceptable), and a list of all unit operations and major streams.
What gets checked
- Scope document states explicitly what is included and excluded from the PFD boundary
- Sketch shows planned layout with unit operations in boxes and streams as directed arrows — not text descriptions
- At least five unit operations and eight streams are included — sufficient complexity for a meaningful P&ID in M3
Common mistakes
- Choosing a single-unit process (one reactor, no separation) — too simple to produce a meaningful PFD or P&ID
- Not planning the layout before drawing — mid-drawing rework is far more expensive than planning the layout on paper first
Resources
Foundationstart here
Depthgo deeper
What a verifier looks for
- Confirm scope document states the system boundary explicitly — not just 'the process'.
- Confirm the layout sketch shows unit operations and streams — not a written description.
- Confirm ≥5 unit operations and ≥8 streams are in scope.
Draw the PFD and Complete the Heat and Material Balance
3–4 weeks (4–5 hrs/week)
Draw the complete Process Flow Diagram using standard ISA or IEC chemical engineering symbols. Include all major equipment, process streams, utility connections, and stream identification numbers. Complete a heat and material (H&M) balance table documenting flow rate, composition, temperature, pressure, and enthalpy for each process stream. The H&M balance table is the data backbone of the PFD — without it the diagram is a schematic, not a process document.
Proof required
Submit your PFD drawing (PDF or high-resolution image) and H&M balance table: all streams with flow rate, composition, temperature, pressure, and enthalpy values, with data sources cited.
What gets checked
- PFD uses standard symbols (ISA 5.1 or equivalent) and labels all equipment with tag numbers and stream with stream numbers
- H&M balance table covers all process streams with all five parameters (flow, composition, temperature, pressure, enthalpy)
- All H&M balance data cites its source — simulation output, thermodynamic data book, or cited calculation
Common mistakes
- Drawing unit operations without stream numbers — unlabelled streams make the H&M balance table unusable
- H&M balance table with estimated or missing values — every cell must have a real value or be explained as 'not applicable'
Resources
Foundationstart here
Depthgo deeper
What a verifier looks for
- Confirm PFD uses consistent standard symbols and all equipment has tag numbers, all streams have stream numbers.
- Confirm H&M balance table covers all process streams — no stream is undocumented.
- Confirm H&M balance data sources are cited — simulation output, NIST, or calculation reference.
Develop the P&ID and Review for Operability
3–4 weeks (3–4 hrs/week)
Develop a Piping and Instrumentation Diagram (P&ID) from the PFD, adding all process piping, control loops, safety instrumentation (PSVs, emergency shut-down valves), and utility connections. Review the P&ID against an operability checklist: does every unit have a start-up bypass? Are all instrumentation loops complete (sensor → controller → final element)? Can the system be safely shut down? Have the P&ID reviewed by a chemical or process engineer.
Proof required
Submit your P&ID drawing (PDF or high-resolution image) and operability review record (≥500 words): checklist of operability issues found, changes made, reviewer name and role, ≥3 challenge questions and your responses.
What gets checked
- P&ID adds control loops, safety devices, and piping details not shown on the PFD — it is not simply the PFD with pipe sizes added
- Operability review identifies ≥2 specific issues and documents the changes made to address them
- Reviewer has chemical or process engineering experience — peer review without domain expertise does not count
Common mistakes
- Submitting a P&ID that is a copy of the PFD with pipe diameters added — a P&ID must show instrumentation, control loops, and safety devices
- Reviewer without process engineering background — P&ID review requires domain expertise to identify control loop completeness and safety instrumentation gaps
Resources
Foundationstart here
Depthgo deeper
What a verifier looks for
- Engineering Design Triad check: M1–M3 together produce a design artifact (PFD + P&ID drawings), an analysis artifact (H&M balance table with all streams), and a documentation artifact (operability review record + P&ID review) — confirm all three types are present.
- Confirm P&ID adds instrumentation, control loops, and safety devices that are absent from the PFD — it must be a distinct document.
- Confirm operability review identifies ≥2 specific issues and the changes made.
- Confirm reviewer has chemical or process engineering experience.
- The Proof Accessibility Rule applies — draw.io (free), DWSIM (free), NIST WebBook (free), and IChemE free resources are all accessible without commercial licence.