24/7 X 365  DAY 

EVENING 

NIght

The Dawn of a New Era in HF2M

Human Factor Fatigue Mitigation

Chrono Engineering has developed over more than 50 years fatigue mitigation, and chronobiology research applications, into enterprise software that helps organizations eliminate fatigue improve workforce safety, and optimize operational performancev

Yeaars pioneering
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Copyrighted modules
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Fortune companies served
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Shiftworkers worldwide
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Built on 51 years of Scientific Innovation

Engineering Time Through Science

For more than five decades, our scientists and engineers have advanced the understanding of human time biology and fatigue. Our chronobiology and biomathematical models power
enterprise solutions that deliver measurable value in the world’s most demanding 24/7 environments.

Our vision

Fatigue is not a tolerance to manage. It is a risk to eliminate.

ChronoEngineering builds scientifically validated software for the largest 24/7 operations on earth — predictive tools that see fatigue risk forming before it ever reaches a shift, a schedule, or a site.

Over five decades of chronobiological research, distilled into a working platform. This is not a new cookie. It is a new discipline — engineered around the human day, evening and night.

Since 1975

Pioneering shiftwork chronobiology

51 years

Spearheading fatigue & scheduling solutions

US Government partner

National Association for Shiftwork Health

Global reach

Deployed across rail, aviation, energy, safety & defense

Four software systems

01

FIRM 2 Monitor

Continuous fatigue-risk surveillance

02

Smart Relief

Fitness-for-Duty call-in intelligence

03

LENS

Lifestyle Education & Notifications

04

Visual AIM

Roster fatigue-risk assessment

The platform

Three tools. One continuous defense against fatigue.

Each module operates independently and compounds when deployed together — from long-term monitoring to the moment a phone rings at 3 a.m.

01

FIRM 2 Monitor

Fatigue Intelligent Risk Model — 24/7

Captures fatigue risk before it reaches the site. FIRM 2 Monitoring outperforms other fatigue models — compatible with and superseding regulations and industry best practices.

02

Smart Relief

The ultimate risk-free call-in service

Uses biomathematical modeling to select the right person for the right job — ensuring they are the most optimally alert to perform the job safely.

03

LENS

Lifestyle Education & Notifications for
Shiftworkers

A mobile companion that translates each unique schedule into personal best practices — when to sleep, what to eat, when caffeine helps, when fatigue peaks.

How it works

An operating layer for the biological reality of 24/7 work.

FIRM 2 Monitor

Fatigue Intelligent Risk Model — 24/7

Captures fatigue risk before it reaches the site. FIRM 2 Monitoring continuously evaluates every crew, every shift, and every downstream schedule — compatible with and superseding existing regulations and industry best practices.

Smart Relief

The moment absentee coverage becomes safety

LENS best practices

Personalized · schedule-aware · daily

No one else does this. LENS turns a shift schedule into a detailed set of activities for on- and off-hours — designed to prepare each worker for optimum performance on their exact rotation.

Visual AIM

Fatigue Intelligent Risk Model — 24/7

Assess the risk of the roster you have today, then chart the precise lifestyle strategies and countermeasures that lower it — an educational bridge into biomathematical scheduling.

Evidence. Research. Results.

Scientifically Validated

Our technology is built on rigeroua scientific research and verified in real-world operational environments across the globe.

Peer-Reviewed Papers
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Years of Field Validation
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Organizations Served
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Workers Impacted
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Industries We Serve

Oil & Gas

Rail

Healthcare

Mining

Utilities

Manufacturing

Founders

Two engineers, one discipline.

ChronoEngineering was built by equal founders — the inventor of the FIRM model and the architect who turned it into working software for the world’s 24/7 operations.

David E Nash

Founder · Managing Partner

Civil, Industrial and Mechanical Engineer with a Master of Organizational Behavior. Sole original owner, founder and inventor of FIRM and the FIRM Fatigue Scale; co-developer of FIRM 2 Monitoring with Dr. Dave Johannsen. Over five decades — 51 years — spearheading fatigue and scheduling solutions for hundreds of Fortune 500 companies. Founder of the National Association for Shiftwork Health.

Dr. Dave Johannsen

Co-Founder · Chief Architect

Chief architect and managing partner of ChronoEngineering — the entire architect of ChronoEngineering. BS Electrical Engineering; MS Computer Science, Caltech 1978; PhD Computer Science, Caltech 1981 (doctoral thesis: Silicon Compilation). Lead designer of FIRM & FIRM 2 Monitoring, PRISM, LENS, LENSmobile, Smart Relief, Visual AIM, ISOP and TSS. Architect of the PASS (Predictive Analytic Scheduling Solutions) engine.

Half a century of firsts

1975 — 2024

1975–80

Copyrights 88 unique scheduling systems for 24/7 processes

1984

Introduces Activity-Rest Cycles (ARC) models for personal risk prevention

1988

Founds the National Association for Shiftwork Health

1994–96

Ships first Bid-pack Master Scheduler for US railroads

1999–00

Delivers ERA — proportional staffing efficiency software for US police

2004–06

Launches LENS — the yearly Lifestyle-Planner for individual shiftworkers

2013–14

Ships ISOP scheduler and the Smart Relief Task Scheduling System (TSS)

2018–22

Deploys Smart Relief call-in software system

1983

Reschedules all US Air Traffic Control Centers (Rapcon, Tracon, Class 4 & 5)

1986

Founds the Chronoengineering Department, Ohio Div. of Safety & Hygiene

1992–93

Builds the first Smart Relief system for balanced circadian phase

1998

Copyrights the first viable 4–10 hour schedule for 24/7 fixed-start operations

2000–04

Develops FIRM — Fatigue Intelligent Risk Model (FIRM II, 2019)

2007–12

Introduces PRISM — Predictive Risk Intelligent Safety Module

2015–18

Releases LENS mobile app for shiftworkers

2022–24

FIRM 2 Monitoring — captures fatigue risk before it reaches the site

Library

Videos, science & field reports.

A growing archive of demonstrations, peer-reviewed research and operational case studies from the field.

Video

The chronobiology of shiftwork

Coming soon · YouTube

Video

Inside the FIRM 2 monitoring system

Coming soon · YouTube

Research

Best practice benchmarking against FIRM-2

Scientific report · PDF

Research

Best practice benchmarking against FIRM-2

Scientific report · PDF

Questions

What operators ask first.

Not seeing your question? Reach the team directly — we prefer real conversations to canned answers.

What industries is ChronoEngineering built for?

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Begin

Eliminate fatigue risk before it reaches your site.

A short conversation is the fastest way to see whether ChronoEngineering fits your operation.