Currently, members of the public have no idea how to submit petitions for rulemaking to the agency and actively participate in the rulemaking process, because the agency does not make this information available like other agencies do. So OPM should post easily-accessible, plain-English guidance on its public website regarding how the public can submit and comment on petitions for rulemaking.
See, for example, the FDA website (http://www.fda.gov/AboutFDA/ContactFDA/CommentonRegulations/default.htm) and the FAA website (http://www.faa.gov/regulations_policies/rulemaking/petition/).
This guidance could also be published in the Federal Register/CFR -- Federal law arguably requires the agency to publish this information -- see 5 USC 552(a)(1), requiring each agency to publish, for the guidance of the public, descriptions of the employees to whom and the methods by which the public may make submittals, like petitions.
An open petition process could allow the public to share ideas and expertise to improve the agency's work. If the agency publishes and encourages public comments on incoming petitions, this would also jump-start public conversations on the agency's work.