Case Studies

These case studies illustrate how Alcoa is acting upon its commitment to sustainable development throughout the world. We are pleased with this progress, but look forward to achieving even more.

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USA - 2011

Human Performance Program Reduces Errors, Boosts Safety Performance


Since implementing a science-based human performance safety program in 2009, Alcoa’s U.S. Primary Products (USPP) business has reduced its total recordable incident rate by more than 40% and lost workday rate by 85%.


Human performance focuses on the way people, programs, processes, work environment, organization, and equipment work together as a system. The individual employee is at the middle of that system. Any flaws in the system impact the performance of the individual, and any flaws in the individual impact the system.


Human performance teaches employees how to recognize error and error-likely situations to predict, reduce, manage, and prevent fatalities and injuries from occurring.


The scientific research behind human performance shows that people work in one of three performance modes at any point in time, with each having its own error rate. These are:

  • Skills-based mode: Routine, repetitive, and habitual work that requires minimal thought. The error rate while in this mode is one in 1,000.
  • Rule-based mode: The employee, who has the necessary knowledge, skills, and experience, must follow an established rule. Error rate while working in this mode is one in 100.
  • Knowledge-based mode: A new or infrequent work situation where the employee does not have the knowledge, skills, and experience necessary. Error rate ranges from one in two to one in 10.


“Learning to recognize what performance mode I’m operating in was enlightening to me,” said Wayne Guest, safety leadership and human performance team leader for the Mt. Holly, South Carolina, location. “If I’m in knowledge-based mode, for example, I now know that I need to stop and seek out help or utilize one of the other human performance tools to assist me, or I could be heading toward a problem.”


Human performance also teaches employees how to avoid error traps, which are conditions or situations that people may fall into without recognizing it and are proven through research to be leading causes of injuries. The 10 traps are: stress; high work load; poor communications; vague or poor work guidance; overconfidence in work and/or abilities; infrequent or first time performing a task; distractions; first working day following time off greater than four days; and the end of a shift or work cycle.


To ensure employees are aware of which mode they are operating in and the likely error traps, USPP use various tools at its five operating locations that include:

  • Eight hours of human-performance training for all employees, 10 hours for supervisors and 24 hours for employee advocates;
  • Daily pre-job briefing on at least one job to assess mode and address error traps;
  • Conversation at the start of each shift to engage employees in discussing modes and traps;
  • Stop and seek help process that has specific criteria on when an employee needs to stop a job and get help; and
  • Peer-to-peer observations performed on a formal and informal basis.


Following a full year of employee training in 2009, USPP posted a 2010 total recordable incident rate that was 15% lower than the 2009 rate. As the business deployed the pre-job briefings, stop and seek help process, and other human performance tools, it achieved a 39% rate reduction in the first six months of 2011 compared to the same period the previous year. This was despite a significant increase in risk due to the startup of idled production at locations in Massena, New York, Ferndale, Washington and Wenatchee, Washington.


“I’ve always had a ‘get it done’ attitude, but looking back, I can see how this contributed to making errors,” said Guest. “Human performance has taught me to slow down and recognize potential error traps that I may encounter whenever I shift performance modes. That’s been a real cultural change.”



Total recordable incident rate represents the number of injuries and illnesses resulting in days away from work, job transfer or restriction, medical treatment, or other recordables per 100 full-time workers.