Key Points
- Different teams or contractors working in the same area at the same time.
- Creates interference risks that require active coordination and communication.
- Closely related to SIMOPS but focuses on the human coordination aspect.
- Must be identified during permit planning and managed throughout execution.
Definition
Co-activity describes situations where different teams, contractors, or disciplines work in the same area at the same time, creating overlapping hazards that must be actively managed. In industrial environments such as refineries, power plants, and construction sites, co-activity is one of the most common sources of safety incidents because the actions of one team can directly affect the safety of another. For example, a welding team performing hot work near a team conducting gas-line maintenance creates a compounded risk scenario that neither team's individual risk assessment would fully address. Effective co-activity management requires shared situational awareness, joint toolbox talks, coordinated scheduling, and real-time visibility into all active permits in a given area. Digital permit-to-work systems play a crucial role by automatically flagging potential conflicts when multiple permits are issued for overlapping locations or timeframes. Unlike SIMOPS, which is a broader operational planning concept, co-activity focuses specifically on the human coordination challenge — ensuring that every team on site understands what other work is happening around them and what additional precautions are needed. Failure to manage co-activity has been identified as a contributing factor in numerous major industrial accidents, making it a key focus area for safety regulators and standards bodies worldwide.
Related Terms
Simultaneous Operations (SIMOPS)
SIMOPS refers to multiple work activities taking place at the same time in the same area. These activities may interact and create additional risks. Proper coordination is essential to avoid conflicts.
Control of Work (CoW)
Control of Work is a broader operational framework that governs how work is planned, authorized, and executed safely across a site. It includes PTW processes, risk assessments, isolations, and coordination of simultaneous activities. CoW ensures that all work is visible, controlled, and aligned with site rules and safety requirements. In practice, it is the overarching system that connects different safety processes into one structured approach.
Dynamic Risk Assessment
Dynamic risk assessment refers to continuous evaluation of risks during the execution of work as conditions change. Unlike pre-planned assessments, it is performed in real time by workers on site. It is critical in environments where conditions evolve rapidly. In practice, it supports situational awareness and safe decision-making during execution.
PTW Coordinator
The PTW Coordinator oversees and manages the overall permit process on site. They ensure permits are consistent, conflicts between activities are identified, and safety standards are followed. This role is critical in environments with multiple simultaneous work activities. In practice, the coordinator acts as the central hub of work control.
More in Risk & Safety
Job Safety Analysis (JSA)
A Job Safety Analysis is a structured process used to break down a task into individual steps and identify hazards associated with each step. For every identified risk, appropriate control measures are defined to reduce or eliminate the hazard. JSA is typically prepared before work begins and is often linked directly to the permit. In practice, it ensures that work is systematically thought through rather than executed based on assumptions.
Point of Work Risk Assessment (PWRA)
PWRA is a risk assessment performed at the exact location where work will take place just before starting. It verifies that planned controls are still valid in the actual environment. It acts as a final validation between planning and execution.
Residual Risk
Residual risk is the level of risk that remains after all control measures have been implemented. It cannot be fully eliminated but must be reduced to an acceptable level. Understanding residual risk is critical for decision-making.
Last Minute Risk Assessment (LMRA)
LMRA is a final safety check performed immediately before starting work. It ensures that nothing has changed since the original assessment. It is often performed by the work team on site.
Frequently Asked Questions
How is co-activity different from SIMOPS?
SIMOPS is a broader concept covering all simultaneous operations. Co-activity specifically refers to the interaction between different work teams or contractors sharing the same space, emphasizing the coordination challenge.
What controls are used to manage co-activity risks?
Common controls include toolbox talks with all teams present, shared hazard boards, coordinated work schedules, physical barriers between work zones, and real-time permit visibility through digital systems.
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Pirkka Paronen
CEO, Gate Apps
CEO of Gate Apps, expert in digital permit-to-work and HSEQ software.
