[1] D. D. Black, “Management of Safety–A Systems Engineering Approach,” Ph.D. Thesis, University of Ulster, Belfast, 2008.
[2] Health and Safety Executive, “Permit-to-Work Systems (IND(G) 98),” 3rd Edition, HSE Books, London, 1997.
[3] Health and Safety Executive, “Essentials of Health and Safety at Work,” HSE Books, London, 2006.
[4] Noble Denton Associates, “ROGS: The Railways and Other Guided Transport Systems (Safety) Regulations 2006–A Guide to ROGS,” July 2009. http://www.rail-reg. gov.uk.
[5] P. G. Bishop and R. E. Bloomfield, “The SHIP Safety Case Approach,” Proceedings of International Conference on Computer Safety, Reliability and Security (SAFECOMP ’95), Belgirate, 1995, pp 437-445.
[6] N. G. Leveson, “Safeware System Safety and Computers,” Addison-Wesley, White Plains, 2001.
[7] D. Attwood, F. Kahn and B. Veitch, “Occupational Accident Models–Where have We been and Where are We Going?” Journal of Loss Prevention in the Process Industries, Vol. 19, No. 6, 2006, pp. 664-682.
[8] M. E. C. Hull, K. Jackson and A. J. J. Dick, “Requirements Engineering,” 2nd Edition, Springer, Heidelberg, 2005.
[9] Health and Safety Executive, “Guidance on Permit-to- Work Systems: A Guide for the Petroleum, Chemical and Allied Industries,” HSE Books, London, 2005.
[10] International Association of Oil & Gas Producers, “Guide- lines on Permit to Work (PTW) Systems,” Report No. 6.29/189, January 1993, pp. 1-30.
[11] D. D. Black, M. E. C. Hull and K. Jackson, “+PFW–A Process for System Safety,” 2009, unpublished.
[12] UK Statute Law Database, “Health and Safety at Work (Northern Ireland) Order 1978,” No. 1039(NI9), July 1978, pp. 1-10.
[13] D. D. Black, M. E. C. Hull and K. Jackson, “Systems En- gineering and Safety–A Framework,” 2009, unpublished.
[14] A. Mengolini and L. Debarberis, “Safety Culture Enhancement through Implementation of IAKA Guidelines,” Journal of Reliability and Systems Safety, Vol. 92, No. 4, 2007, pp. 520-529.
[15] R. Crook, D. Ince and B. Nuseibeh, “On Modelling Access Policies: Relating Roles to their Organisational Context,” Proceedings of 13th IEEE International Conference on Requirements Engineering, 2005, pp157-166.
[16] C. Lowe, “A Human Factors Perspective on Safety Management Systems,” Improvements in System Safety, Spr- inger, Heidelberg, 2008.