Override Safety Advisor (Exaquantum/OSA)

Exaquantum Override Safety Advisor is an application to assist users in the monitoring, tracking and reporting of instrument overrides.

Additionally, Exaquantum/OSA provides support for performing risk assessments based on live, updating plant conditions prior to the implementation of an instrument(s) override. The risks associated with overrides can be greatly reduced if it is easier to identify what the consequences would be at the time of application.

Exaquantum/OSA Overview

Assessments help to identify areas of concern based on the plant’s safety design and the potential for dangerous scenarios and conditions, which may manifest in other instruments with multiple hazards. An instrument override may leave one hazard with ‘Sufficient’ protection. However, this instrument may also be part of another hazard, or multiple hazards that may provide ‘Insufficient’ protection. Decision makers are therefore able to validate their decisions quickly, prior to implementation of the override(s).

Exaquantum/OSA Overview

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  • Reduce the uncontrolled use of instrument overrides
  • Improve safety practices and processes with inherent enforcement of overrides policies and procedures
  • Improve awareness of the current safety state of the process by highlighting risks associated with active instrument overrides
  • Prevent potential unsafe situations by performing risk assessments before the implementation of instruments overrides
  • Understand the impact of overrides throughout the plant and evaluate the propagation of risk on other equipment and instruments
  • Improve safety compliance by automatically collecting history and evidence of policy enforcement for all instrument overrides
  • Enhanced traceability by providing audit trailing, logging and reporting to support regulators and investigators requirements
  • Improved assessments and workflows with fewer user errors and streamlined shift handovers

Exaquantum/OSA is a web-based application providing risk assessment assistance to users before overriding instruments or equipment by:

  • Displaying the current plant safety status of all instrument overrides
  • Assessing the impact of overrides before implementation
  • Identifying the effects on hazards associated with equipment that may manifest in other instruments when an override is performed
  • Identifying required authorization levels before overrides are implemented
  • Reporting actions that do not adhere to policy
  • Presenting information to streamline shift handovers
  • Reporting on historical override activations, assessments and authorizations

Data Collection
The underlying Exaquantum historian provides Exaquantum/OSA with a powerful, integrated, cost-effective platform for collecting and storing data from different sources via OPC DA, OPC A&E and OPC HDA, independent of the system vendor. OPC HDA has been expanded within Exaopc (Yokogawa’s OPC server) to allow historical Alarms & Events to be recovered by Exaquantum following a communications interruption.

Risk Assessment
Exaquantum/OSA provides functionality to assist operators to perform override risk assessments prior to implementation. This allows users to make informed decisions mitigating the potential risks associated with any override.
Exaquantum/OSA’s risk assessment results are provided in an intuitive plant graphical display containing clearly highlighted risk areas with additional details available by drilling into selected areas.

Exaquantum/OSA is configured using safety design information obtained from the HAZOP (Hazard and Operational Analysis), which has determined the compensating measure (for a SIS device in bypass) and that they provide adequate risk reduction. If a HAZOP is revised, then the user must update the Exaquantum/OSA database accordingly.  Yokogawa can provide safety consultancy services including HAZOP to support this process.

Plant Overview
Exaquantum/OSA provides a near real-time graphical overview of the plant that allows operators to view the current state of their equipment and instrumentation.

Exaquantum/OSA provides a full and comprehensive list of all current overrides including the start time and duration of all overrides and shows the safety levels for each instrument

Shift Handover
Exaquantum/OSA provides a concise and easy to understand Shift Handover Report containing all override activities current and in shift, making shift handovers simple, accurate and efficient.

Policy Enforcement
Exaquantum/OSA encourages good practices and policy enforcement by:

  • Highlighting and reporting overrides that were not assessed prior to their execution
  • Identifying and reporting assessments which did not have the appropriate approvals
  • Forcing assessments to be re-evaluated when plant conditions change during the assessment process
  • Helping to prevent additional overrides from occurring in areas that have an excess of active overrides

Authorization Identification

Based on the severity of risk, Exaquantum/OSA will inform users which personnel must provide their approval before executing an override. This can also be configured for manual input of authorization information from an external process such as a Permit to Work system. This streamlines the approval process while maintaining standards and safety policy guidelines.

Web User Interface
Exaquantum/OSA provides secure web based displays and reports for users to access from local and remote locations that requires no client software installation.


Dynamic user reports contain drill-downs, filtering and sorting options to allow analysis of the data. Reports can be exported to multiple formats (Excel, Word, PDF) and scheduled for email at configurable periods.

Instrument Overrides Report
This report displays instruments that have been overridden, or equipment taken offline, for a user specified time range.

Shift Overview Report
This report displays an overview of the inhibit KPIs for each shift.

Shift Details Report
This report displays a complete view of all override activity that took place during a shift period and includes the Shift Details, Shift Notes, Instruments Overridden, Equipment Taken Offline and Equipment Status.

Shift Details Report 

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Assessment Overview Report
This report displays an overview list of all assessments that have been performed during a specified time range.

Assessment Detail Report
This report displays a detailed static view of an assessment. The following can be identified from this report:

  • Overridden or offline Instruments/Equipment
  • Instruments that were overridden or Equipment taken offline prior to the assessment
  • Instruments that were impacted by overridden or offline instruments/equipment
  • The risk factors for overridden or offline instruments/equipment

Assessment Detail Report

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Product Overview

Discover the challenges of monitoring safety system performance throughout the lifetime of the plant and how the Exaquantum safety management solutions from Yokogawa overcome these challenges by dynamically monitoring safety system performance.

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