Change Management Models are helpful because they help explain and simplify the complex change processes in order for change practitioners and leadership to guide people through a transition. No change management model is the same and each one is designed to address different needs. It is always good to have multiple techniques in your pocket to help address changes that come your way. Complex Responsive Process (CRP) and ADKAR are both popular and effective models that address change. We can explore the differences between the two and discuss when it makes the most sense to use one or the other.
Complex Responsive Process is a model based on behavioral theory. It's premise is that people are social creatures and that when one person communicates, others respond to the communication and the cycle repeats itself. In this model management cannot be effective from outside the group and because human behavior is unpredictable, it is impossible to accurately predict how a behavior will influence change in an organization. As a leader, you are not outside of the system dictating; instead you are part of the whole environment – working within it.
Complex Responsive Process suggests using self-organizing interaction to create knowledge sharing within an organization, with the manager as a driving force. This model relies on team work and interaction between people within the organization in order to come to one common goal. It suggests that the more diversity there is in the group and the more comfortable the group is with one another, the more novel the ideas will be that emerge from it. It is somewhat of a democratic model in that the group comes together with a number of different ideas, the team builds upon those ideas, and highly productive results emerge. At the same time, in an environment that is not diverse and where people are uncomfortable with one another, CRP will dictate a decline in communication and a negative impact on the organization.
Prosci® ADKAR® Model is a widely used and popular change model that is based on individual progression through five stages of change: Awareness, Desire, Knowledge, Ability and Reinforcement. This framework is used to understand how change occurs and what levers we can pull to help it occur more rapidly and effectively. Its primary focus is on the individual level rather than the community or organizational level. 
These 5 stages of ADKAR are essential in the success of this change model. They build upon one another and must be addressed sequentially for success. Awareness is the first building block that helps address "why" the change is needed. Desire is the second building block that helps change practitioners identify who supports the change and who is resisting. Desire is therefore a stage of wanting to change. Knowledge is the third building block that helps participants decipher what the change is and how it impacts them specifically. Ability is the fourth building block. It is when the change actually occurs and individuals build capability to execute/operate in the changed environment. Reinforcement is the fifth building block where the change is institutionalized and embedded into standard, organizationally supported processes and behaviors. Leadership at all levels is critical to the Reinforcement stage where long term sustainable change is secured.
This model works to ensure the rate of individual change matches that of the organization. ADKAR advocates that people change and not organizations. It suggests that change is seen at an organizational level only once a tipping point of individuals have committed to the change.
Complex Responsive Process is a good change model to use within a team framework where individuals are actively involved in sharing a change and open to working together to reach a common goal. This model is best suited for people who are able to build off of one another and brainstorm in a group effort. CRP is ideal for teams who are willing to mature together, and in turn, eventually learn more about themselves and one another throughout the entire process. ADKAR would be best suited for a project in which individuals may need to grow and learn at different rates, while the change is occurring. This model benefits change efforts where resistance is present on a relatively large scale. Additionally, it fosters individual growth and allows for professional and personal growth.
CRP and ADKAR both have merits as models of organizational change. ADKAR focuses on the individual change rate, whereas CRP proposes a joint action where everyone designs the change and grows together. Both models can be beneficial and even used at the same time, but change practitioners must read the climate of the organization to know which model best fits the situation.
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