The Project Scheduling Problem with Non-Deterministic Activities Duration: A Literature Review

Purpose: The goal of this article is to provide an extensive literature review of the models and solution procedures proposed by many researchers interested on the Project Scheduling Problem with nondeterministic activities duration. Design/methodology/approach: This paper presents an exhaustive literature review, identifying the existing models where the activities duration were taken as uncertain or random parameters. In order to get published articles since 1996, was employed the Scopus database. The articles were selected on the basis of reviews of abstracts, methodologies, and conclusions. The results were classified according to following characteristics: year of publication, mathematical representation of the activities duration, solution techniques applied, and type of problem solved. Findings: Genetic Algorithms (GA) was pointed out as the main solution technique employed by researchers, and the Resource-Constrained Project Scheduling Problem (RCPSP) as the most studied type of problem. On the other hand, the application of new solution techniques, and the possibility of incorporating traditional methods into new PSP variants was presented as research trends. Originality/value: This literature review contents not only a descriptive analysis of the published articles but also a statistical information section in order to examine the state of the research activity carried out in relation to the Project Scheduling Problem with non-deterministic activities duration.Peer Reviewe

A hierarchical approach to multi-project planning under uncertainty

We survey several viewpoints on the management of the planning complexity of multi-project organisations under uncertainty. A positioning framework is proposed to distinguish between different types of project-driven organisations, which is meant to aid project management in the choice between the various existing planning approaches. We discuss the current state of the art of hierarchical planning approaches both for traditional manufacturing and for project environments. We introduce a generic hierarchical project planning and control framework that serves to position planning methods for multi-project planning under uncertainty. We discuss multiple techniques for dealing with the uncertainty inherent to the different hierarchical stages in a multi-project organisation. In the last part of this paper we discuss two cases from practice and we relate these practical cases to the positioning framework that is put forward in the paper

A hierarchical approach to multi-project planning under uncertainty.

We survey several viewpoints on the management of the planning complexity of multi-project organisations under uncertainty. A positioning framework is proposed to distinguish between different types of project-driven organisations, which is meant to aid project management in the choice between the various existing planning approaches. We discuss the current state of the art of hierarchical planning approaches both for traditional manufacturing and for project environments. We introduce a generic hierarchical project planning and control framework that serves to position planning methods for multi-project planning under uncertainty. We discuss multiple techniques for dealing with the uncertainty inherent to the different hierarchical stages in a multi-project organisation. In the last part of this paper we discuss two cases from practice and we relate these practical cases to the positioning framework that is put forward in the paper.Choice; Complexity; Framework; Hierarchical models; Management; Manufacturing; Methods; Multi-project organisations; Planning; Project management; Project planning; Uncertainty;

The geography of strain: organizational resilience as a function of intergroup relations

Organizational resilience is an organization’s ability to absorb strain and preserve or improve functioning, despite the presence of adversity. In existing scholarship there is the implicit assumption that organizations experience and respond holistically to acute forms of adversity. We challenge this assumption by theorizing about how adversity can create differential strain, affecting parts of an organization rather than the whole. We argue that relations among those parts fundamentally shape organizational resilience. We develop a theoretical model that maps how the differentiated emergence of strain in focal parts of an organization triggers the movements of adjoining parts to provide or withhold resources necessary for the focal parts to adapt effectively. Drawing on core principles of theories about intergroup relations, we theorize about three specific pathways—integration, disavowal, and reclamation—by which responses of adjoining parts to focal part strain shape organizational resilience. We further theorize about influences on whether and when adjoining parts are likely to select different pathways. The resulting theory reveals how the social processes among parts of organizations influence member responses to adversity and, ultimately, organizational resilience. We conclude by noting the implications for organizational resilience theory, research, and practice.Accepted manuscrip

A methodology for integrated risk management and proactive scheduling of construction projects.

An integrated methodology is developed for planning construction projects under uncertainty. The methodology relies on a computer supported risk management system that allows to identify, analyze and quantify the major risk factors and derive the probability of their occurrence and their impact on the duration of the project activities. Using project management estimates of the marginal cost of activity starting time disruptions, a proactive baseline schedule is developed that is suffciently protected against the anticipated disruptions with acceptable project makespan performance. The methodology is illustrated on a real life application.Risk; Risk management; Management; Scheduling; Construction; Planning; Uncertainty; Factors; Probability; Impact; Project management; Cost; Time; Performance; Real life;

Relax-and-fix heuristics applied to a real-world lot-sizing and scheduling problem in the personal care consumer goods industry

This paper addresses an integrated lot-sizing and scheduling problem in the industry of consumer goods for personal care, a very competitive market in which the good customer service level and the cost management show up in the competition for the clients. In this research, a complex operational environment composed of unrelated parallel machines with limited production capacity and sequence-dependent setup times and costs is studied. There is also a limited finished-goods storage capacity, a characteristic not found in the literature. Backordering is allowed but it is extremely undesirable. The problem is described through a mixed integer linear programming formulation. Since the problem is NP-hard, relax-and-fix heuristics with hybrid partitioning strategies are investigated. Computational experiments with randomly generated and also with real-world instances are presented. The results show the efficacy and efficiency of the proposed approaches. Compared to current solutions used by the company, the best proposed strategies yield results with substantially lower costs, primarily from the reduction in inventory levels and better allocation of production batches on the machines

Economic resilience : including a case study of the global transition network

This paper explores the dynamic properties of organisms and ecosystems that make them so resilient and capable of adapting to changing circumstances, allowing them to maintain an overall condition of coherence, wholeness and health while living in balance within the resources of the planet. Key principles of resilient ecological systems are explored including: self-regulation; positive and negative feedback; diversity; scale and context; cooperation; emergence and novelty; and ecological tipping points. In contrast, market based economic systems can produce unstable growth with unintended destruction of cultural and species diversity and homogenisation of global life-styles. The paper re-examines fundamental economic principles using insights from biological evolution and ecosystem dynamics to establish a foundation for more resilient economies. This involves experimenting with different models in different communities to find patterns of sustainable production and exchange appropriate to local regions. Fundamental steps in this direction include the emergence of self-organising local communities based on creative experimentation, re-localisation of core sectors of the economy (food, energy, health and education), evolution of local currencies and banking practices that support local enterprise and investment in green technologies, stimulation of decentralised renewable energy networks and economic reform aligned with ecological principles. The Transition Network provides a case study of an international community based movement that has been experimenting with putting some of these principles into practice at the local level. The aim of the Transition Network is to support community led responses to peak oil and climate change, building resilience and well-being. The concept of ecological resilience and its application to local economy is hard wired into the values and emerging structure of the network of transition communities across the globe. The movement started in the UK in 2005 and there are now over 1000 Transition initiatives spanning 34 countries across the world. Many attribute the success and phenomenal growth of the Transition Network to its emerging holographic structure that mimics cell growth within living organisms. Growing a more resilient food system in the face of the twin challenges of natural resource scarcity and climate change is central to the Transition movement. A set of principles for a post carbon resilient food economy in the UK are offered. These include an 80% cut in carbon emission in the food sector by 2050, agricultural diversification, prioritization of farming methods that establish and enhance carbon sinks, phasing out of dependence on fossil fuels in food growing, processing and distribution, promoting access to nutritious and affordable food, as well as promoting greater access to land for growing food in urban and peri-urban areas. Practical examples of Transition related projects in the food sector are presented across the following themes: access to land, low carbon production methods, food distribution systems, health and community gardens and orchards, and collaborative ownership models