Challis International is the leading global provider of SAFOP (or eHAZOP) studies.

Our leadership position is reflected in our track record of completing 400 studies in 30 countries over 30 years.

Our Managing Director, Dr David Challis, has personally conducted over 200 SAFOP studies.

Our offerings and approach are differentiated by :


Many organisations use the standard node based SYSOP, SAFAN and OPTAN processes only which can be grossly inadequate for many complex projects. To assure safety, security and operability, SAFOP may require additional processes including, but not limited to :

  • a quality assurance review of the reports and studies that underpin the design,
  • a review of the design at system level (eg Key SLD's, Emergency SLD's, UPS SLD's, PDCS/ENMC Architectures etc) and at node level,
  • a review of the philosophies, strategies and plans for construction, changeover and commissioning,
  • brainstorming processes to capitalise on the collective learnings of participants and identify issues and deficiencies in other projects and facilities and the actions required to avoid them.

The SAFOP process requires customisation to reflect not only the above, the specific risks and issues implicit in the design (eg Supply Authority Interfaces, EMC, IEC Ex, Harmonics etc) and the stage of development of the design, but most importantly, the end clients needs, concerns and expectations. Our SAFOP processes are now 8th generation and vary significantly from those used by other suppliers in the marketplace that reflect the standard SAFOP technology developed circa 1987.


We have found no commercially available software tool or product that meets the specific requirements for a SAFOP study and that can be readily customised to meet the requirements of each client and study. Consequently, in 1996 we developed a proprietary system for planning, executing, reviewing and managing SAFOP or eHAZOP studies. Our proprietary SAFOP system provides clients with the following major benefits

  • Access to a data base of 50,000 line items that have been completed in other SAFOP studies to help stimulate thinking and brainstorming, identify potential deficiencies in the design in question and to learn from others. Line items may be reviewed by a study team and the learning's from others applied to the design in a way that ensures anonymity and confidentiality - it is also not possible to identify the source organisation or business that contributed that line item,
  • As the system is password controlled and web based, the client and contractor can be either trained/authorised to set up their own studies eg node set up, guideword and promptword set up, worksheet format set up etc) or involved in a 3 way conversation with a Challis International Accredited Chairperson to set up the study in real time,
  • Provide the structure and rigour to assure study team discipline (adherence to the agreed agenda and topic), structure (facilitate a rigorous thought process and deliverable) and consistency (assure the concerns and deficiencies identified and reviewed are done so consistently and without bias,
  • Incorporate broader company concepts and models (eg Risk Assessment Matrix) to align the SAFOP team thinking and SAFOP review outcomes with other review processes (HAZOP, HAZID, ENVID, QRA, SIMOPS etc),
  • Enables SAFOP studies to not only achieve superior outcomes (ie be more effective) but also achieve these outcomes more efficiently through facilitating focused discussions, in specific areas in the worksheet at the right time and avoiding 'off topic' discussions,
  • Enables the review process to be completed anywhere across the globe in real time. The outcomes of large studies often require review by participants in many different countries following the completion of the study workshop. Our SAFOP technology enables study participants to provide comments on the line items of interest in real time which may be shared amongst study participants to stimulate thought/be leveraged by other reviewers. This process has been found to be particularly useful is seeking resolution of complex issues where agreement could not be reached at the workshop.


Our SAFOP Chairpersons are not process facilitators. Each has an average of 30 years experience in leading complex technical SAFOP studies (EHV, Complex Dynamic Study Reports, Cogeneration) and complex SAFOP teams (eg JV teams, consortia teams) in culturally diverse and sensitive environments. Our highly experienced persons therefore bring technical SAFOP content value added, SAFOP process value added and SAFOP cultural diversity value added - making sure the process and group dynamic work for all participants, to the table. We ensure that our Chairpersons clearly contract their role with the contractor, the client and the study team before the commencement of the study workshop.

We also have a large pool of experienced and trained study secretaries to support study chairpersons if required for the study or by the client.



Please contact : Dr David Challis