Project Time and Budget Monitor and Control

With the marketing competitiveness growing, it is more and more critical in time and budget control of each project. This paper discusses that in the construction phase, how can a project manager be successful in time and budget control. This paper also evaluates some pitfalls the project manager will meet in his endeavors to monitor and control the project. There are many methods and five kind pitfalls are discussed in this paper, it reveals that to be successful, the project manager must concern all this methods and avoid pitfalls successfully.Key words: Project; monitor and control; time control; cost control; ranking the priority; CPM; non-delay approach; precedence; optimal timing; crashing; pitfal

A two-level genetic algorithm for the multi-mode resource-constrained project scheduling problem

This paper presents a genetic algorithm for the multimode resource-constrained project scheduling problem (MRCPSP), in which multiple execution modes are available for each of the activities of the project. The objective function is the minimization of the construction project completion time. To solve the problem, is applied a two-level genetic algorithm, which makes use of two separate levels and extend the parameterized schedule generation scheme by introducing an improvement procedure. It is evaluated the quality of the schedule and present detailed comparative computational results for the MRCPSP, which reveal that this approach is a competitive algorithm

Uma metaheurística para a programação de projectos com multi-modos e recursos limitados

Este artigo apresenta uma nova abordagem (MM-GAV-FBI), aplicável ao problema da programação de projectos com restrições de recursos e vários modos de execução por actividade, problema conhecido na literatura anglo-saxónica por MRCPSP. Cada projecto tem um conjunto de actividades com precedências tecnológicas definidas e um conjunto de recursos limitados, sendo que cada actividade pode ter mais do que um modo de realização. A programação dos projectos é realizada com recurso a um esquema de geração de planos (do inglês Schedule Generation Scheme - SGS) integrado com uma metaheurística. A metaheurística é baseada no paradigma dos algoritmos genéticos. As prioridades das actividades são obtidas a partir de um algoritmo genético. A representação cromossómica utilizada baseia-se em chaves aleatórias. O SGS gera planos não-atrasados. Após a obtenção de uma solução é aplicada uma melhoria local. O objectivo da abordagem é encontrar o melhor plano (planning), ou seja, o plano que tenha a menor duração temporal possível, satisfazendo as precedências das actividades e as restrições de recursos. A abordagem proposta é testada num conjunto de problemas retirados da literatura da especialidade e os resultados computacionais são comparados com outras abordagens. Os resultados computacionais validam o bom desempenho da abordagem, não apenas em termos de qualidade da solução, mas também em termos de tempo útil.As the complexity of projects increases, the requirement of an organized planning and scheduling process is enhanced. The need for organized planning and scheduling of a construction project is influenced by a variety of factors (e.g., project size and number of project activities). To plan and schedule a construction project, activities must be defined sufficiently. The level of detail determines the number of activities contained within the project plan and schedule. So, finding feasible schedules which efficiently use scarce resources is a challenging task within project management. In this context, the well-known Resource Constrained Project Scheduling Problem (RCPSP) has been studied during the last decades. In the RCPSP the activities of a project have to be scheduled such that the makespan of the project is minimized. So, the technological precedence constraints have to be observed as well as limitations of the renewable resources required to accomplish the activities. Once started, an activity may not be interrupted. This problem has been extended to a more realistic model, the multi-mode resource constrained project scheduling problem (MRCPSP), where each activity can be performed in one out of several modes. Each mode of an activity represents an alternative way of combining different levels of resource requirements with a related duration. Each renewable resource has a limited availability such as manpower and machines for the entire project. The objective of the MRCPSP problem is minimizing the makespan. While the exact methods are available for providing optimal solution for small problems, its computation time is not feasible for large-scale problems. This paper presents a genetic algorithm-based approach (MM-GAV-FBI) for the multi-mode resource constrained project scheduling problem. The idea of this new approach is integrating a genetic algorithm with a schedule generation scheme. This study also proposes applying a local search procedure trying to improve the initial solution. The chromosome representation of the problem is based on random keys. The schedule is constructed using a schedule generation scheme (SGS) in which the priorities of the activities are defined by the genetic algorithm. The experimental results of MM-GAV-FBI on project instances show that this approach is an effective method for solving the MRCPSP

A survey of recent methods for solving project scheduling problems

This paper analyses the current state of research regarding solution methods dealing with resource-constrained project scheduling problems. The intention is to present a concentrated survey and brief scientific overview on models, their decision variables and constraints as well as current solution methods in the field of project scheduling. The allocation of scarce resources among multiple projects with different, conflicting decision variables is a highly difficult problem in order to achieve an optimal schedule which meets all (usually different) of the projects’ objectives. Those projects, e.g. the assembly of complex machinery and goods, consume many renewable, e.g. workforce/staff, and non-renewable, e.g. project budget, resources. Each single process within these projects can often be performed in different ways – so called execution modes can help to make a schedule feasible. On the other hand the number of potential solutions increases dramatically through this fact. Additional constraints, e.g. min/max time lags, preemption or specific precedence relations of activities, lead to highly complex problems which are NP-hard in the strong sense

A survey of recent methods for solving project scheduling problems

This paper analyses the current state of research regarding solution methods dealing with resource-constrained project scheduling problems. The intention is to present a concentrated survey and brief scientific overview on models, their decision variables and constraints as well as current solution methods in the field of project scheduling. The allocation of scarce resources among multiple projects with different, conflicting decision variables is a highly difficult problem in order to achieve an optimal schedule which meets all (usually different) of the projects’ objectives. Those projects, e.g. the assembly of complex machinery and goods, consume many renewable, e.g. workforce/staff, and non-renewable, e.g. project budget, resources. Each single process within these projects can often be performed in different ways – so called execution modes can help to make a schedule feasible. On the other hand the number of potential solutions increases dramatically through this fact. Additional constraints, e.g. min/max time lags, preemption or specific precedence relations of activities, lead to highly complex problems which are NP-hard in the strong sense

Algorithms for scheduling projects with generalized precedence relations.

Project scheduling under the assumption of renewable resource constraints and generalized precedence relations, i.e. arbitrary minimal and maximal time lags between the starting and completion times of the activities of the project, constitutes an important and challenging problem. Over the past few years considerable progress has been made in the use of exact solution procedure for this problem type and its variants. We review the fundamental logic and report new computational experience with a branch-and-bound procedure for optimally solving resource-constrained project scheduling problems with generalized precedence relations of the precedence diagramming type, i.e. start-start, start-finish, finish-start and finish-finish relations with minimal time lags for minimizing the project makespan. Subsequently, we review and report new results for several branch-and -bound procedures for the case of generalized precedence relations, including both minimal and maximal time lags, and demonstrate how the solution methodology can be expected to cope with other regular and nonregular objective functions such a smaximizing the net present value of a project.Networks; Problems; Scheduling; Algorithms; Functions; Net present value;

An Exact Algorithm for the Mode Identity Project Scheduling Problem

In this paper we consider the non-preemptive variant of a multi-mode resource constrained project scheduling problem (MRCPSP) with mode identity, in which a set of project activities is partitioned into disjoint subsets while all activities forming one subset have to be processed in the same mode. We present a depth-first branch and bound algorithm for the resource constrained project scheduling problem with mode identity. The proposed algorithm is extended with some bounding rules to reduce the size of branch and bound tree. Finally, some test problems are solved and their computational results are reported

Mapping optimization techniques in project management

An important function of the project management is to optimize the project in various phases and at different levels. From sourcing and allocation to scheduling and even dealing with uncertainties, the science of operation research (OR) has played an important role in this area. So far, many papers have been published using the optimization science to make various decisions regarding the project management. This study aims to investigate all papers published on the application of optimization in the project management from 1940 to 2019 and shows: a) how the trend has changed over this 79 years period, b) to what direction the trend has changed, c) determines the interesting topics of the recent years, and d) which subjects are more attractive as future studies as the applications of the optimization techniques in the project management

A survey of variants and extensions of the resource-constrained project scheduling problem

The resource-constrained project scheduling problem (RCPSP) consists of activities that must be scheduled subject to precedence and resource constraints such that the makespan is minimized. It has become a well-known standard problem in the context of project scheduling which has attracted numerous researchers who developed both exact and heuristic scheduling procedures. However, it is a rather basic model with assumptions that are too restrictive for many practical applications. Consequently, various extensions of the basic RCPSP have been developed. This paper gives an overview over these extensions. The extensions are classified according to the structure of the RCPSP. We summarize generalizations of the activity concept, of the precedence relations and of the resource constraints. Alternative objectives and approaches for scheduling multiple projects are discussed as well. In addition to popular variants and extensions such as multiple modes, minimal and maximal time lags, and net present value-based objectives, the paper also provides a survey of many less known concepts. --project scheduling,modeling,resource constraints,temporal constraints,networks