An SMS can be as complex or as simple as it needs to be for the size of organisation and number of employees concerned. However, if it contains statements that pilots are subsequently able to use to back up their arguments as to why they won't be going flying that day, then they can do so without fear because it could be something that a private owner could be compelled to sign up to before being permitted to employ licenced pilots.
Have a look at Chapter 12 of this ICAO Document, especially Appendix 1, the Sample Safety Policy Statement.
http://legacy.icao.int/osg/isd/afi/R...S%20Manual.pdf
If a private or corporate owner HAD to sign up to this or something similar before they could employ pilots to fly their aircraft, then the pilots would be protected. It would be dead easy to throw it back in their faces if they're applying pressure for you to go flying in poor weather for example.
Apologies for the formatting if it comes out wrong but read what's below and adjust to suit the individual owners/organisation.
ICAO Sample Safety Policy Statement
Safety is the first priority in all our activities. We are committed to implementing, developing and improving strategies, management systems and processes to ensure that all our aviation activities uphold the highest level of safety performance and meet national and international standards.
Our commitment is to:
a) Develop and embed a safety culture in all our aviation activities that recognizes the importance and value of effective aviation safety management and acknowledges at all times that safety is paramount;
b) Clearly define for all staff their accountabilities and responsibilities for the development and delivery of aviation safety strategy and performance;
c) Minimize the risks associated with aircraft operations to a point that is as low as reasonably practicable/achievable;
d) Ensure that externally supplied systems and services that impact upon the safety of our operations meet appropriate safety standards;
e) Actively develop and improve our safety processes to conform to world-class standards;
f) Comply with and, wherever possible, exceed legislative and regulatory requirements and standards;
g) Ensure that all staff are provided with adequate and appropriate aviation safety information and training, are competent in safety matters and are only allocated tasks commensurate with their skills;
h) Ensure that sufficient skilled and trained resources are available to implement safety strategy and policy;
i) Establish and measure our safety performance against realistic objectives and/or targets;
j) Achieve the highest levels of safety standards and performance in all our aviation activities;
k) Continually improve our safety performance;
l) Conduct safety and management reviews and ensure that relevant action is taken; and
m) Ensure that the application of effective aviation safety management systems is integral to all our aviation activities, with the objective of achieving the highest levels of safety standards and performance.