Porter’s 5 forces is an external/environmental model of analysis.  The 5 forces are specifically

• existing competition: the competitive relationship in the organizational field/marketplace
• bargaining power of suppliers:  level of dependence/ who has more leverage
• bargaining power of consumers: level of dependence/ who has more leverage
• barriers to entrance: laws/costs/difficulties getting established
• substitutions: possible options / replacements for the consumer
• compliments (add on to the original 5 forces): other items/services the make the item more desirable and dispersed.

The 5 forces assumes that strategic positioning of the firm creates sustainable competitive advantage.  By analyzing the marketplace, the environment in which the firm exists, the firm can identify opportunities and threats, know when to enter and leave the marketplace, know how to respond to changes and how to position the firm for best results.  The 5 Forces is an external focus, precluding attention on internal resources; it presumes a homogeneity of resource distribution/ the mobility of resources, and as such sees positioning and external analysis as the arena in which to create sustainable competitive advantage.  It is not strategy per se, but guidelines of where to gather data and where to look for advantage.

Barney resisted the focus on external positioning countering that sustainable competitive advantage can and does come from internal resources.  It is an internal, resource-based analysis model.  Barney asserted that there are three types of resources: physical; organizational; and human, and that these resources could be a firm’s sustainable competitive advantage.  This suggests resource immobility; a heterogeneous distribution of resources amongst competitors and the possibility of creating create sustainable competitive advantage that could not be replicated by the competition.  For a resource to offer a sustainable competitive advantage it has to be these 4 qualities.  Valuable; Rare; worthy of imitation; have no replacement/equivalent.

A sociologist would criticize the lack of/minimizing of political, historical and social forces that shape organizational structure and behavior.  She would point out patterns of isomorphism, organizational tendencies to search for legitimacy and security, the irrational perceptions of problems and solutions, structural inertia and difficulties of changing; the fact that organizational behavior was reflective of traditional behavior and not of rational decision making on the part of most internal actors.  She would note that the very process of strategy would reflect (to some degree) the personal goals of stakeholders, and that many organizational decisions reflected organizational goals not in alignment with stated mission or economic plans.  She would also criticize the premise of the rational actor model in general and the presumption of ahistorical values that are projected on all societies (and people) as if there was universal similarity of expectations and desires across time and space.

Resource Dependence asserts the immobility of resources such that a competitive advantage can exists in the internal resources of a firm.  Stinchcombe asserted that organizations were and only could be created with the existing social technology available.  That an organization was, in fact, limited in form and function by the society in which it was formed.  Furthermore, that the organization would hold onto features of the original time/place even in the face of newness and competition.  If this is true, it is not obvious that an organization would be free to create an unlimited or unconditional internal competitive advantage;  if the social technology was not present, however advantageous a process might be, it would not exist as a possible creation for the organization.  Also- if organizational form persisted over extended periods, it might reflect a population ecological view that an organization would hold onto older forms regardless of the opportunity to innovate a new competitive advantage; it might not/would not necessarily change.  In general, any sociologist would take umbrage with any organizational model that failed to emphasis the importance of social, political and historical forces on organization action and behavior.  To simply ignore the greater social milieu in which an organization exists would be a fundamental flaw in any model including Resource Dependence.