What is the leading alternative to the "stages" model of grieving? In "Cautioning Health-Care Professionals: Bereaved Persons Are Misguided Through the Stages of Grief" by Stroebe et al. the popular "5 stage model" of Kübler-Ross is incorrect. Stroebe et al. argue:


  the regularities of stage theory are too simplistic and limited; they
  fail to represent the complex emotions and processes of grief and
  grieving. They also lack empirical foundation. Using stages in
  practice is potentially harmful, and yet an (perhaps the) ultimate
  goal of theory construction in our field is to enable health-care
  professionals to provide tangible help to those who need it.


What are the leading theories/models of bereavement and how are they superior?
According to "Theories of Grief and Bereavement" by Boerner et al. (2015) the leading theories are:


The Four Component Model from Bonanno and Kaltman


Context in which loss occurs 
Subject meanings associated with loss
Changes in representation of the lost loved ones over time
Presence of coping and emotion processes

The Dual Process Model from Stroebe and Schut


Loss-oriented coping
Restoration-oriented coping



The article also notes that further work needs to be done in terms of:


Effects of inter-personal relations
Influences of cultural background
Biological aspects