Stochastic modelling of maintenance flexibility in value for money assessment of PPP road projects

Zhang, J and Yuan, X X (2021) Stochastic modelling of maintenance flexibility in value for money assessment of PPP road projects. Construction Management and Economics, 39(2), pp. 173-191. ISSN 01446193

Abstract

Maintenance flexibility has been promoted as a value driver for long-term public–private partnerships (PPPs). However, the value and risk associated with this value driver have not been properly quantified in the Value for Money (VfM) assessment literature. To bridge the gap, a novel stochastic modelling methodology is proposed to characterize the complex interactions among the lifecycle cost (LCC), performance deterioration and maintenance strategies. Four different maintenance strategies are designed to emulate the practice in the traditional and PPP delivery methods. The LCC includes the direct maintenance cost, user cost, residual value, and payment deduction, the last three often being neglected in VfM assessments. Simulation-based optimization and dynamic programming analysis are used to determine the probability distributions of the LCC and the VfM. A hypothetical highway PPP project under an availability payment model is selected as a case study. The results show that maintenance flexibility is indeed able to reduce the LCC for the private party. However, this private efficiency, if not properly regulated, could cause a reduced asset residual value and an increased user cost, making the public party worse off. In addition, for all potential maintenance strategies, the public sector is found to retain significant lifecycle cost risk, largely in the form of user cost.

Item Type: Article
Uncontrolled Keywords: deterioration uncertainty; flexibility; life-cycle cost; public–private partnerships; value for money
Index terms: maintenance cost, road project, interaction, modelling, lifecycle, dynamic programming, public sector, probability distribution, partnership, delivery method, case study, efficiency, value-for-money, methodology, strategy, simulation-based optimization, deterioration
Subjects: evaluation, infrastructure engineering, management, financial management, performance management, research methods, algorithms, administrative law, statistical analysis, behavioral psychology, delivery method, partnership management, data collection methods, material degradation and durability, analytical methods, project delivery
Topics: Stakeholder Management, Procurement, Business Strategy, Engineering Principles, Construction Materials, Research Practice, Project Management, Digital Applications, Legal Issues, Value Management, Quality Management
Descriptive scope: 5 PCTEA

N.B. Descriptive scope is a count of how many of the five facets of empirical research are indicated by the words used in title, abstract and keywords. It is not intended as a judgement on the research; merely a count of the kind of word we would expect to indicate Phenomenon, Concepts, Theoretical framing, Empirical techniques, Analytical techniques. If all five are present, then a code of “5 PCTEA” will indicate this. If you feel the coding for this record is questionable, we welcome discussion around the terms we matched or the way we categorized them. The facet you would expect may not be coded, or a facet may be coded inappropriately. This can also bear on a larger question, of which facets should be treated as defining in construction management research. Please get in touch, and we will look at it. More details here