Integrating the permit to work to an access control system
Article by Gavin Halse and Henry Boshoff
The possibility of someone inexperienced or unqualified entering a dangerous area in a plant or active construction area is very real. This can lead to a tragic accident.
Many companies implement site access control systems to mitigate against this risk. Site access control can present an opportunity to improve overall safety on site when it is integrated with the electronic permit to work process.
In this article we discuss access control in general and then some of the opportunities for improving safety by integrating site access control with the electronic permit to work system.
What is access control?
Access control is a method to control passage into or out of an area. In this article we are focusing on access control in industrial sites, where potentially dangerous operations are underway, or where construction and maintenance is underway.
Plant access control is normally through a gate, turnstile or doorway. The area itself is protected by a physical barrier such as fencing or walls. Unlike a typical gate, access through a turnstile ensures that only one person can move through at a time, improving control. Turnstiles are often located at strategic entry points and are often managed by the site security function.
Individuals are typically identified by a mechanism such as a card scanner, RFID tag (radio frequency identification), fingerprint (or other biometric) identification, a secret keypad code etc.
Restricted areas can be controlled at multiple levels. For example, the whole site may be protected at the main gate. Each main operational area might also be separately controlled. Control might even be localised to specific plant areas or sections of buildings.
In our experience most, existing access control systems were originally installed for security or loss control reasons and often to record time and attendance information. They were not always designed with safety as the main goal.
How can access control improve safety?
Restricting access to an area of the plant is one way to help ensure that work takes place safely. A well-designed access control system can prevent unauthorised personnel from entering dangerous areas of the plant, as well as ensuring that all people in the area are tracked and authorised to be there.
Access control system information can be useful for tracing people during an emergency. Over time, this data can also be used to flag risks such as individuals working excessive hours; or flag unusual patterns such as individuals entering dangerous areas for the first time.
Is it possible to use IntelliPERMIT in combination with a DCS or PLC to manage isolations using software only? Read more about software assisted isolations.
Benefits of integrating access control with the permit to work
Integrating the access control system to the electronic permit to work system holds a number of benefits by introducing an additional level of control:
- Individuals can only be granted access to an area to work if they have a valid permit in the system.
- Leaving the area at the end of a routine shift can be prevented if there are remaining permit actions (for example a person cannot leave a plant area until all his locks are removed, and the handover process is signed off).
- A record of site access and permit activity can be kept and analysed for patterns of behaviour to identify areas of concern or for improvement.
- Contractor work on site can be better managed, for example where occasional workers need to undergo additional checks.
- Inductions and other prerequisites for working on the site can be verified.
- Master data could be pulled from the access control system to populate user records as well as related biometric or access card data resulting in less administration.
Is it really necessary to have access control as part of an electronic permit to work system?
Access control is not a requirement for an electronic permit to work system but having it can further support work taking place safely.
If an existing access control system is in place and an electronic permit system is being implemented, it is important to include the system integration requirements during the initial specification. If on the other hand there is no existing access control system in place, there might be an opportunity to improve overall safety and control of work on site by implementing the two systems together.
Unintended consequences and other safety considerations
Integrating access control to improve safety can inadvertently introduce new and different risks. For example, a fence and turnstile arrangement can introduce a new hazard if evacuation is necessary as a result of a gas leak near the main entrance (for example). Sometimes these unintended consequences are subtle and careful design is therefore necessary to avoid introducing new risk.
A simple mechanism to override site access control in an emergency or during an evacuation is recommended. Temporary “soft” overrides are also good practice, provided a reason is then supplied which can later be followed up.
Multiple (different) forms of access control on site can be confusing and also increase safety risk. This might occur for example where different RFID cards from different vendor systems are needed on different sections of plant.
The decision whether or not to grant access might need to satisfy conflicting requirements (business rules). For example, one security requirement might be a blanket restriction on access to an area overnight, while a maintenance requirement might require after-hours access to the same area. These conflicts need to be identified and resolved in the overall system logic so that these multiple objectives can be met without compromising safety.
Designing a site access control system
When considering a new access control system or integration, it is important to consider the big picture and ideally architect a single integrated solution. The overall system should be designed to “fail safe” and extra care is necessary to identify and avoid conflicting requirements between the individual sub-systems.
In complex environments, multiple RFID (radio frequency ID) applications may exist e.g. RFID tags that identify people, RFID tags that identify fixed equipment, RFID tags that identify movable equipment etc. To reduce complexity these should, if possible use a single, integrated RFID tag standard and a common infrastructure.
Access control devices such as biometric readers, card readers or secret passcodes can also serve to validate users and approve transactions in other electronic systems (such as maintenance, process control systems and business systems). The goal should therefore be to design for simplicity where all transactions can ideally be validated the same way.
Standalone systems should be avoided if they could cause confusion or introduce conflicting requirements with other on-site systems.
When selecting an access control technology, it is important to verify that the system supports open interfaces that allow easy integration with the processes taking place in other systems.
Alternative (back up) mechanisms of authenticating users should be considered, for example a RFID access card as the primary mechanism, a fingerprint as a backup and a password in exceptional circumstances. This prevents work from being held up due to faulty devices, or in areas where readers do not exist.
Management of the access control database
When selecting a new system or when planning an integration, it is important to consider the various processes necessary to maintain and update the information in the central database.
An individual’s site access privileges are often maintained by the site security/loss control function. However, safety information is normally maintained by the safety department, induction information by the training department while basic personal information including medical records etc might be updated by the human resources or clinic function. All of these functions therefore need to ideally use an integrated system and aligned to common processes.
Part time employees or contractors that must attend to specific jobs after hours sometimes need to be granted access immediately without waiting for the human resources function to arrive in the morning. Authorised persons therefore need to be able to grant temporary access rights while ensuring safety is not compromised in these situations.
Well designed and integrated access control can certainly reduce risk and improve safety on site and we would recommend it be considered.
Before implementing an integrated access control system, it is important to consider the wider implications, including allowing for different means of identification, integrating systems from different vendors, and maintaining the system data between different functions etc.
To avoid the access control system creating unintended safety risks in itself, controlled overrides should be allowed in special circumstances; for example, during an emergency evacuation.
Conflicting requirements between site security, maintenance and safety as well as other functions should be carefully considered when designing the integrated processes.
When done properly, an integrated access control and permit to work system allows for a number of benefits that will definitely reduce risk and improve safe work. This integration is worth considering for these benefits alone.
The IntelliPERMIT team at Adapt IT has successfully integrated a number of access control systems to IntelliPERMIT in different environments. If you have any comments or questions in this regard, please don’t hesitate to contact us.