Showing papers by "Mario Vanhoucke published in 2015"

A comparison of the performance of various project control methods using earned value management systems

Abstract: Two new project schedule control procedures using EVM are proposed: EVM-FPB and EVM-SNB.The effort spent by a project manager provides a functional distinction for the discussed project control approaches.The placement of control points in the project is inspired by critical chain/buffer management.Monte Carlo simulations are used to calculate tolerance limits for the control approaches and quantify their performance.The EVM-SNB approach is found to outperform the other project control approaches. Recent literature on project management has emphasised the effort which is spent by the management team during the project control process. Based on this effort, a functional distinction can be made between a top down and a bottom up project control approach. A top down control approach refers to the use of a project control system that generates project based performance metrics to give a general overview of the project performance. Actions are triggered based on these general performance metrics, which need further investigation to detect problems at the activity level. A bottom up project control system refers to a system in which detailed activity information needs to be available constantly during the project control process, which requires more effort. In this research, we propose two new project control approaches, which combines elements of both top down and bottom up control. To this end, we integrate the earned value management/earned schedule (EVM/ES) method with multiple control points inspired by critical chain/buffer management (CC/BM). We show how the EVM/ES control approach is complementary with the concept of buffers and how they can improve the project control process when cleverly combined. These combined top down approaches overcome some of the drawbacks of traditional EVM/ES mentioned in the literature, while minimally increasing the effort spent by the project manager. A large computational experiment is set up to test the approach against other control procedures within a broad range of simulated dynamic project progress situations.

Empirical Evaluation of Earned Value Management Forecasting Accuracy for Time and Cost

Abstract: The ability to accurately forecast a project’s final duration and cost is essential to successful project management. The technique of earned value management (EVM) is considered to provide an effective methodology for obtaining such forecasts; however, this has not yet been adequately tested on empirical data. Therefore, the accuracy of the most commonly used EVM time and cost forecasting methods is evaluated on a diverse and qualitative database consisting of 51 real-life projects. As most projects originate from the construction industry, an explicit focus on these construction projects is provided. Moreover, the desired real forecasting outcomes based on the actual project progress data are also supported by a Monte Carlo simulation study. It is demonstrated that highly accurate time and cost forecasts can be obtained by applying the EVM methodology. Furthermore, the best performing forecasting methods for the projects in the considered database are identified, also taking into account timelin...

A multivariate approach for top-down project control using earned value management

Abstract: Project monitoring and the related decision to proceed to corrective action are crucial components of an integrated project management and control decision support system (DSS). Earned value management/earned schedule (EVM/ES) is a project control methodology that is typically applied for top-down project schedule control. However, traditional models do not correctly account for the multivariate nature of the EVM/ES measurement system. We therefore propose a multivariate model for EVM/ES, which implements a principal component analysis (PCA) on a simulated schedule control reference. During project progress, the real EVM/ES observations can then be projected onto these principal components. This allows for two new multivariate schedule control metrics (T2 and SPE) to be calculated, which can be dynamically monitored on project control charts. Using a computational experiment, we show that these multivariate schedule control metrics lead to performance improvements and practical advantages in comparison with traditional univariate EVM/ES models. Two multivariate project schedule control metrics are presented using well-known EVM metrics.Principal component analysis is used to build a correlation reference and to test the multivariate metrics.A large simulation study compares the novel control approach with the current best practice.Improvements are obtained in comparison with the traditional project control approach.

A new scheduling technique for the resource–constrained project scheduling problem with discounted cash flows

Abstract: In this paper, we discuss the resource–constrained project scheduling problem with discounted cash flows. We introduce a new schedule construction technique which moves sets of activities to improve the project net present value and consists of two steps. In particular, the inclusion of individual activities into sets, which are then moved together, is crucial in both steps. The first step groups the activities based on the predecessors and successors in the project network, and adds these activities to a set based on their finish time and cash flow. The second step on the contrary does so based on the neighbouring activities in the schedule, which may but need not include precedence related activities. The proposed scheduling method is implemented in a genetic algorithm metaheuristic and we employ a penalty function to improve the algorithm’s feasibility with respect to a tight deadline. All steps of the proposed solution methodology are tested in detail and an extensive computational experiment shows that our results are competitive with existing work.

Study of the stability of earned value management forecasting

Abstract: In this paper, the authors focus on the stability of earned value management (EVM) forecasting methods. The contribution is threefold. First of all, a new criterion to measure stability that does not suffer from the disadvantages of the historically employed concept is proposed. Second, the stability of time and cost forecasting methods is compared and contrasted by means of a computational experiment on a topologically diverse data set. Throughout these experiments, the forecasting accuracy is reported as well, facilitating a trade-off between accuracy and stability. Finally, it is shown show that the novel stability metric can be used in practical environments using two real-life projects. The conclusions of this empirical validation are found to be largely in line with the computational results.

On the design of custom packs: grouping of medical disposable items for surgeries

Abstract: A custom pack combines medical disposable items into a single sterile package that is used for surgical procedures. Although custom packs are gaining importance in hospitals due to their potential benefits in reducing surgery setup times, little is known on methodologies to configure them, especially if the number of medical items, procedure types and surgeons is large. In this paper, we propose a mathematical programming approach to guide hospitals in developing or reconfiguring their custom packs. In particular, we are interested in minimising points of touch, which we define as a measure for physical contact between staff and medical materials. Starting from an integer non-linear programming model, we develop both an exact linear programming (LP) solution approach and an LP-based heuristic. Next, we also describe a simulated annealing approach to benchmark the mathematical programming methods. A computational experiment, based on real data of a medium-sized Belgian hospital, compares the optimised resu...

Introduction to earned duration

Abstract: The management of project baseline schedules has evolved significantly since the development of the Gantt chart in the early 20th century (Gantt, 1919). In the next few decennia, the Program Evaluation and Review Technique/Critical Path Method and the Precedence Diagram Method (Fondahl, 1987), and more recently, the Critical Chain Project Management technique (Goldratt, 2002) saw the light.

Decomposition-based heuristics for the integrated physician rostering and surgery scheduling problem

Abstract: In this paper, a comparison and validation of various priority rules for the Integrated Physician Rostering and Surgery Scheduling Problem (IPSSP) under different objective functions is made. We integrate three constructive heuristic types with two corresponding priority rule classes in order to obtain a solution for the combined physician rostering and surgery scheduling problem. Twelve priority rules for the surgery assignments and six priority rules for the physician rostering are used to schedule the surgeries in the operating theatre on a weekly basis, while generating adequate rosters for the physicians that maximizes their preferences. Our goal is to provide a suitable heuristic for every problem type, problem size and problem structure for the hospital manager to use in every possible condition. The problem type represents the most occurring objectives and goals according to literature. The problem size depicts the size of the hospital and its corresponding utilization. The problem structure defines the different demands of the physician roster and the surgery schedule. It can be shown that for every situation a fitting heuristic can be provided. These high-quality decomposition-based constructive heuristics can also be used in meta-heuristics to generate good solutions. Most importantly, we have established general recommendations with respect to the use of the different proposed heuristics in different hospital settings.

Heuristic Methods for the Resource Availability Cost Problem

Abstract: In this chapter, an Invasive Weed Optimization (IWO) algorithm for the resource availability cost problem is presented, in which the total cost of the (unlimited) renewable resources required to complete the project by a prespecified project deadline should be minimized. The IWO algorithm is a new search strategy, which makes use of mechanisms inspired by the natural behavior of weeds in colonizing and finding a suitable place for growth and reproduction. All algorithmic components are explained in detail and computational results for the RACP are presented. The procedure is also executed to solve the RACP with tardiness (RACPT), in which lateness of the project is permitted with a predefined penalty.

On the use of Schedule Risk Analysis for Project Management

Abstract: The purpose of this paper is to give an overview on the existing literature and recent developments on the research on Schedule Risk Analysis (SRA) in Project Management (PM) to measure the sensitivity of activities and resources in the project network. SRA is a technique that relies on Monte-Carlo simulation runs to analyze the impact of changes in activity durations and costs on the overall project time and cost objectives. First, the paper gives an overview of the most commonly known sensitivity metrics from literature that are widely used by PM software tools to measure the time and cost sensitivity of activities as well as sensitivity for project resources. Second, the relevance of these metrics in an integrated project control setting is discussed based on some recent research studies. Finally, a short discussion on the challenges for future research is given. All sections in this paper are based on research studies done in the past for which references will be given throughout the manuscript.

Operating theatre modelling: integrating social measures

Abstract: Hospital resource modelling literature is primarily focussed on productivity and efficiency measures. In this paper, our focus is on the alignment of the most valuable revenue factor, the operating room (OR) with the most valuable cost factor, the staff. When aligning these economic and social decisions, respectively, into one sustainable model, simulation results justify the integration of these factors. This research shows that integrating staff decisions and OR decisions results in better solutions for both entities. A discrete event simulation approach is used as a performance test to evaluate an integrated and an iterative model. Experimental analysis show how our integrated approach can benefit the alignment of the planning of the human resources as well as the planning of the capacity of the OR based on both economic related metrics (lead time, overtime, number of patients rejected) and social related metrics (personnel preferences, aversions, roster quality).

The multi-mode resource-constrained project scheduling problem

Abstract: This chapter reports on a new solution approach for the multi-mode resource-constrained project scheduling problem (MRCPSP, MPS | prec | C max ). This problem type aims at the selection of a single activity mode from a set of available modes in order to construct a precedence and a (renewable and nonrenewable) resource-feasible project schedule with a minimal makespan. The problem type is known to be \(\mathcal{N}\mathcal{P}\)-hard and has been solved using various exact as well as (meta-)heuristic procedures. The new algorithm splits the problem type into a mode assignment and a single mode project scheduling step. The mode assignment step is solved by a satisfiability (SAT) problem solver and returns a feasible mode selection to the project scheduling step. The project scheduling step is solved using an efficient meta-heuristic procedure from literature to solve the resource-constrained project scheduling problem (RCPSP). However, unlike many traditional meta-heuristic methods in literature to solve the MRCPSP, the new approach executes these two steps in one run, relying on a single priority list. Straightforward adaptations to the pure SAT solver by using pseudo boolean nonrenewable resource constraints has led to a high quality solution approach in a reasonable computational time. Computational results show that the procedure can report similar or sometimes even better solutions than found by other procedures in literature, although it often requires a higher CPU time.

Blended Learning in Project Management

Abstract: This paper reports on results of experiments in the classroom with students following Project Management (PM) courses using a blended learning approach. It discusses the impact of communication on the student performance on business games as well as the advantage of the use of integrative case studies and their impact on the learning experience of these students. While the performance of students is obtained by marking their quantitative output on the business game or case exercise, their learning experience is measured through an analysis of the course evaluations filled out by these students. Diversity among the test population is guaranteed by testing our experiments on a sample of students with a different background, ranging from university students with or without a strong quantitative background but no practical experience, to MBA students at business schools and PM professionals participating in a PM training.

Generalized Discrete Time-Cost Tradeoff Problems

Abstract: Time-cost tradeoffs have been extensively studied in the literature since the development of the critical path method. Recently, the discrete version of the problem formulation has been extended to various practical assumptions, and solved with both exact and heuristic optimisation procedures, as described in Vanhoucke and Debels (J Sched 10:311–326, 2007).In this chapter, an overview is given of four variants of the discrete time-cost tradeoff problem and a newly developed electromagnetic meta-heuristic (EM) algorithm to solve these problems is presented. We extend the standard electromagnetic meta-heuristic with problem specific features and investigate the influence of various EM parameters on the solution quality. We test the new meta-heuristic on a benchmark set from the literature and present extensive computational results.

The art of project management: A story about work and passion

Abstract: The book contains stories about friendship, ideas, hard work and results on Project Management. It gives you a look into the endeavors done in the past and the ideas that will be done in the future. It tells about the products and ideas of OR-AS and gives you a brief overview of the most important people who inspired us and the OR-AS products. It tells about work, and the passion that has led to the results of the hard work. It’s not a scientific book. It isn’t a managerial book either. It’s just a story ... about work and passion.

A new solution approach to solve the resource-constrained project scheduling problem with logical constraints

Abstract: This paper presents a new solution approach to solve the resource-constrained project scheduling problem in the presence of three types of logical constraints. Apart from the traditional AND constraints with minimal time-lags, these precedences are extended to OR constraints and bidirectional (BI) relations. These logical constraints extend the set of relations between pairs of activities and make the RCPSP definition somewhat different from the traditional RCPSP research topics in literature. It is known that the RCPSP with AND constraints, and hence its extension to OR and BI constraints, is NP-hard. The new algorithm consists of a set of network transformation rules that removes the OR and BI logical constraints to transform them into AND constraints and hereby extends the set of activities to maintain the original logic. A satisfiability (SAT) solver is used to guarantee the original precedence logic and is embedded in a metaheuristic search to resource feasible schedules that respect both the limited renewable resource availability as well as the precedence logic. Computational results on two well-known datasets from literature show that the algorithm can compete with the multi-mode algorithms from literature when no logical constraints are taken into account. When the logical constraints are taken into account, the algorithm can report major reductions in the project makespan for most of the instances within a reasonable time.

Taking sound business decisions: From rich data to better solutions

Abstract: The book gives an introduction to the world of mathematical programming and data analytics and is mainly written for M.Sc. and MBA students at Ghent University, Vlerick Business School and UCL School of Management of University College London. On top of that, the book also contains an overview of research studies and company applications of data-driven modelling technique developed by the Operations Research & Scheduling group, which makes the book potentially relevant for researchers and professionals interested in the new data-driven management approach. The book is free for download via the OR-AS site and will be updated on a regular basis upon requests and comments of the readers.

Classroom experiments on project management communication

Abstract: This manuscript gives a brief overview of three sets of experiments in the classroom with students following a Project Management (PM) course module using a blended learning approach. The impact of communication on the student performance using business games as well as the advantages of the use of integrative case studies and their impact on the learning experience of these students are tested. The performance of students is measured by their quantitative output on the business game or case exercise, while their learning experience is measured by the student evaluations. The experiments have been carried out on a sample of students with a different background, ranging from university students with or without a strong quantitative background but no practical experience, to MBA students at business schools and PM professionals participating in a PM training. The results have been presented at an international workshop on computer supported education in Lisbon (Portugal) in 2015 and details have been published in Vanhoucke and Wauters (2015).