Four offline tools for recording and calculating a process hazard analysis, plus Excel workbooks, guides and worked examples. Everything runs in the browser: no installation and no internet.
New here? Start with the overview. What each tool is for, how information moves between them, which tool to choose – and the hot DRI conveyor fire traced through all of them with consistent numbers (6 pages).
Tip: use Google Chrome or Microsoft Edge. In this browser the tools work, but “Save as… (link file)” is not available – use Download backup (.json) to keep your work.
Saving from this page: on a USB stick or a folder, the browser does not allow Save as… (link file) inside this page. To keep your study in a file, use Open in new tab, or use File ▸ Download backup (.json) here. Work is also kept in this browser automatically.
A full process hazard analysis moves from broad hazard identification to quantified barriers. Each step uses one tool or workbook and hands its results to the next. You do not need every step for every study – the table below helps you choose.
Which tool for which question?
Question
Use
What can go wrong in this area or activity?
HAZID checklist
What deviations can happen at this node, why, and what protects against them?
HAZOP Study Manager or HAZOP workbook
How can this piece of equipment fail, and how bad is it?
FMECA workbook
How likely is it that this protection fails on demand (PFDavg, SIL)?
Fault Tree & PFD Calculator
Given the event happens, how often does each outcome follow?
Event Tree Analysis
Which barriers stand between the threats and the consequences, and which matter most?
Bow Tie Analysis
Traced through every step
Hot DRI conveyor fire – the built-in example in all four tools. The HAZOP finds “no flow – stoppage under load”, the fault tree quantifies the N2 fire protection (gate G-002, PFDavg 0.0285), the event tree uses that gate as a heading, and the bow tie uses it as a barrier.
Steel works gas network PHA – a complete worked study: HAZOP (8 nodes, 46 deviations), FMECA, 3 fault trees, 2 event trees and 2 bow ties sharing the same tags, nodes and recommendations, with a 20-page study report and 437 automated consistency checks.
All example data are illustrative – replace them with site and vendor data before use.
Guides and reference
Document
Format
What it covers
Excel workbooks
Companion workbooks for teams that prefer Excel. Use File ▸ Save As in Excel to keep a filled-in copy in the My studies folder.
Workbook
Version
What it contains
Macro versions: click Enable Content / Enable Macros when opening. Some organisations block macros in files from USB drives, downloads or e-mail – then use the .xlsx versions, or copy the file to a trusted location. If Windows Excel says macros are blocked because the source is untrusted: close Excel, right-click the .xlsm file ▸ Properties ▸ tick Unblock ▸ OK. Macros need desktop Excel; they do not run in Excel for the web or on tablets.
Example files
Every tool also has its examples built in (File ▸ Load example). The files below are the same examples, plus the complete worked PHA. Open them with File ▸ Open file… in the matching tool.Download a file, then open it with File ▸ Open file… in the matching tool.
File
Open with
Content
Requirements
Windows 10 / 11 or macOS with a current Google Chrome or Microsoft Edge (recommended – needed for saving directly to files). Firefox and Safari work with Download / Import backup.
For the workbooks: Microsoft Excel 2016 or later (Microsoft 365 recommended).
No installation, no administrator rights and no internet connection are needed. Nothing you enter is sent anywhere – your data stay in your browser and in the files you save.
If your company blocks files opened from USB drives, copy the whole folder to the computer (for example Documents) and run it from there.
1. What this toolkit is
Four tools for recording and calculating a process hazard analysis (PHA): the HAZOP Study Manager, the Fault Tree & PFD Calculator, Event Tree Analysis and Bow Tie Analysis. They are study-recording tools and calculators, not simulators: what you enter is your study record. Around them are the HAZOP and FMECA Excel workbooks, the HAZID checklist, the HAZOP guidewords, user guides and worked examples.
Each tool is one HTML page that runs in the browser with no installation and no internet connection. Nothing you type is sent anywhere.
2. Quick start
Read the overview (6 pages) if the tools are new to you.
On Launch, choose a tool and click Open here (or Open in new tab).
Try the built-in example first: File ▸ Load example.
Start your own study with File ▸ New, then save it to a file straight away (section 4).
3. The views on this page
Launch – the four tools, the overview and quick links.
Open a tool – the tool on this page, with its purpose, quick start, examples and saving notes beside it. Switch tools with the selector at the top.
Study path – the order of a full PHA, what each step hands to the next, and which tool answers which question.
Library – guides, reference, workbooks and example files.
Guide – this page.
Hold the mouse over any button or link for a short tip.
4. Saving your work
Every tool keeps your work automatically in the browser of the computer you are using. That copy stays on that computer and in that browser only. Keep a file as well:
Link a file (Chrome or Edge):File ▸ Save as… (link file) – the HAZOP tool calls it Save study as…. From then on every change is written to that file. To carry on later, or on another computer, use File ▸ Open file…; if the tool asks, click Reconnect file.
From a USB stick or a folder: save into the My studies folder. Linking a file works only when the tool has its own tab – use Open in new tab. On the Open a tool view the browser blocks it.
On the website: linking a file also works on the Open a tool view. Save to your own computer or network drive.
Backup:File ▸ Download backup (.json) from time to time; Import backup brings it back. This works in every browser.
Always eject the USB stick safely before removing it.
5. Moving results between tools
Fault tree → event tree / bow tie:File ▸ Import fault tree (.fta.json)…, then link an event-tree heading or a barrier to a fault-tree gate; its probability is then calculated, not typed.
HAZOP → fault tree: a deviation with a high risk and a claimed IPL is a candidate for a fault tree of that safeguard. Keep the HAZOP node, deviation and recommendation numbers in the fault tree's title and notes.
FMECA → fault tree: failure modes of protective equipment become the basic events; use the same equipment tags.
Results → HAZOP: write the calculated frequency back into the HAZOP likelihood and recommendations.
The steel works gas network example shows all of these links in one study.
6. Browsers, phones and tablets
Best in Google Chrome or Microsoft Edge on a laptop or desktop.
Firefox and Safari work, but cannot link a file – use Download / Import backup.
On phones and tablets this page works, and the tools open, but their tables and diagrams are made for a wider screen. Use them there for viewing and small edits.
7. Problems and answers
“Save as… (link file)” does nothing or shows an error – use Chrome or Edge, and open the tool in its own tab (Open in new tab)allow the browser to save when it asks.
My study is not there on another computer – browser storage does not travel. Open your saved file with File ▸ Open file….
The tool asks to reconnect the file – the browser needs your permission again after a restart. Click Reconnect file.
Macros are blocked in the workbooks – see the note under Excel workbooks in the Library.
Starting a new class – each learner saves to their own file; old work in the browser can be cleared with File ▸ New in each tool.