The Human Resources Post-Merger Integration Project Plan covers organization planning, policies, benefits, communication, compensation, and HRIS systems.

Excerpt from HR Project Plan 

Initiative / Task Name
Coordination:
Establish HR workstream leader
Select HR workstream participants
Recruit core team
Establish HR workstream meeting schedules
Cadence and frequency
Develop HR workstream detailed plan
Establish HR workstream reporting (task / milestone status)
Updates to HR workstream plans / dashboard
 
Communication:
HR Communication Plan: Communication Matrix
Align with IMO Com plan
Core Messages, Target Audiences, Timing, Delivery Medium(s), FAQs, RACI Matrix
Communication with key HR suppliers / contractors
Insurance benefit administrators, payroll administrators, PMOs, etc.
Benefits conversion information
Health plans, 401K, etc.
 
Organization:
Define acquired company org. structure
Identify formal and informal org. relationships
Determine organization similarities / differences
Gather information on relevant positions
Map acquired company roles to acquiring company roles
Identify organization differences to address
Position titles, areas of overlap, etc.
Align positions & titles
Review / Align job descriptions
Establish new organization structure ...