Abstract:
PPP projects are often complex, unique and dynamic due to high sunk-in costs and long concession period
making it vulnerable to risks (known-unknowns) and uncertainties (unknown-unknowns). Previous
researches focus on risks associated with PPP projects. But these projects are hit by uncertainties which
surfaces as turbulences during the execution as well as the operation stage of the project. The extant
literature does not focus much on the uncertainties manifested in these projects nor does it convey the
stakeholders’ outlook on uncertainties, which has a strong bearing on project management. In order to
ensure sustainability of PPP projects, among other factors, it is important to identify uncertainties that
affect their performance in various phases or leads to uncertain situations. A superset of uncertainties
identified from literature was subsequently expanded and validated by PPP Experts. Stakeholders
perceptions on the fifty-four identified uncertainties likely to manifest in various phases was assessed
through a survey to identify and evaluate the uncertainties that affect the implementation of transport PPP
infrastructure projects as well as explore the perception of stakeholders on project uncertainties for endto-
end sustainability. Differences in opinion among stakeholders on uncertainties often are found to act as
a hurdle for effective implementation of PPPs. It is comforting to note that stakeholders have arrived at a
general understanding on uncertainties since the inception of PPP projects in India, though there is long
way to go. The comprehensive list of the uncertainties brought out in this paper validated by the experts in
this field through their experience gained in managing PPP projects in India over the past two decades,
when given due consideration while developing Concession Agreements in future will help to institutionalise
addressing these unknown unknowns as well as keep the project officers prepared to effectively manage
them as and when they unfold.