Construction Multi-Project Scheduling Model Considering Different Resource Allocation Behavior

2012 ◽  
Vol 174-177 ◽  
pp. 2815-2819 ◽  
Author(s):  
Shu Shun Liu ◽  
Wei Tong Chen

According to previous researches, an investigation through small to mid-size construction contractors showed that 84% of construction contractors execute their projects in a multi-project environment. In a multi-project environment, scheduling problems with resource constraints are much more complicated than those in a single project. One of the most important factors that influence multi-project scheduling problems is resource allocation policy, depending on the types of resources, which can be defined by the way of resource acquisition and sharing behavior. This paper discusses resource allocation mechanism for construction multi-project scheduling issues, and then presents an optimization-based model to resolve resource allocation problems. This research developed a CP-based (Constraint Programming) model, which is capable of handling different optimization objectives such as minimizing total cost, overall project duration, subject to resource assignment combinations for each activity. Based on research results, the influence of different types of resource quantity on multi-project duration is discussed. Moreover, resource competitive behavior among all projects is recognized. It concludes that the effective increment of critical resources can reduce overall project duration. The major goal of this research is to find the relation among duration-cost-resource in a multi-project environment, and provide systematic information for construction parties when making resource allocation decisions.

2012 ◽  
Vol 18 (2) ◽  
pp. 262-279 ◽  
Author(s):  
Piotr Jaskowski ◽  
Anna Sobotka

Current network techniques used for project scheduling presume that there is only one logical sequence of activities. However, in reality, the precedence logic of activities is not necessarily unchangeable. There are two types of relations between activities: fixed (hard) and soft. Current scheduling methods do not differentiate between these two types of relations and require a planner to choose one particular logical sequence based on some assumptions. The paper presents a model that allows for “weakening” the links between activities, i.e. that permits concurrent execution of activities or reversing their order, but this may require additional resource-consuming works or expenditures. The model involves two subtypes of soft logic: REVERSED and CANCELED to represent the soft relations between activities. Its mathematical form is a mixed linear integer programming model of minimizing the project duration without exceeding the allowed budget. The paper presents an example of practical application of the method to scheduling interior finishing works. The results support the argument that using soft logic relations between construction activities provides more flexibility in reducing project duration, activities timing and resource allocation.


2021 ◽  
Vol 13 (17) ◽  
pp. 9956
Author(s):  
Osman Hürol Türkakın ◽  
David Arditi ◽  
Ekrem Manisalı

Resource-constrained project scheduling (RCPS) aims to minimize project duration under limited resource availabilities. The heuristic methods that are often used to solve the RCPS problem make use of different priority rules. The comparative merits of different priority rules have not been discussed in the literature in sufficient detail. This study is a response to this research gap. It compares 17 heuristic priority rules and seeks the best performing heuristic priority rule. This is the first study ever that compares heuristic priority rules by considering combinations of variations in (1) resource allocation procedures, (2) number of activities, (3) number of resource constraints, and (4) resource supply levels. The objective is to understand the relative merits of heuristic rules used in solving the RCPS problem. The findings indicate that the “minimum late finish time” rule generates the shortest predicted project duration when used in parallel resource allocation, whereas the “minimum late start time”, “minimum late finish time”, and the “highest rank of positional weight 2” rules perform best in serial resource allocation. It was also found that parallel resource allocation is slightly superior to serial resource allocation in most instances.


2016 ◽  
Vol 64 (2) ◽  
pp. 383-393 ◽  
Author(s):  
R. Różycki ◽  
G. Waligóra ◽  
J. Węglarz

Abstract In this paper, discrete-continuous project scheduling problems with preemptable activities are considered. In these problems, activities of a project simultaneously require discrete and continuous resources for their execution. The activities are preemptable, and the processing rate of each activity is a continuous, increasing function of the amount of a single continuous resource allotted to the activity at a time. The problem is to find a precedence- and discrete resource-feasible schedule and, simultaneously, continuous resource allocation that would minimize the project duration. Convex and concave processing rate functions are considered separately. We show that for convex functions the problem is simple, whereas for concave functions a special methodology has to be developed. We discuss the methodology for three cases of the problem: no discrete resource constraints, one discrete resource being a set of parallel, identical machines, and an arbitrary number of discrete resources. In each case we analyze separately independent and precedence-related activities. Some conclusions and directions for future research are given.


Author(s):  
Yuval Cohen ◽  
Ofer Zwikael ◽  
Arik Sadeh

Many IT projects and software development projects are very complex and sophisticated involving a large coordinated team. Such projects are a constant part of the operations of software companies such as Microsoft, SAP, Oracle, Google, Yahoo, IBM, and others. Many other companies carry large software projects as part of their IT operations. As a result of the size and complexity of such projects, a rolling horizon approach for their planning and management is not only plausible but also desirable. For large projects, traditional project scheduling techniques cannot provide an optimal and timely solution to minimum project duration under precedence and resource constraints. This paper proposes a technique that allows utilizing non-polynomial (NP) algorithms in a heuristic manner – generating high quality schedules in reasonable time. This approach can be applied efficiently for solving most project scheduling problems. The main advantage of this approach is its ability to dissect the original problem into small sub-problems of a controllable size to which exact techniques can be applied. Thus, it neutralizes the complexity of the applied algorithms (and their non-polynomial growth). Moreover, the same technique could be used for implementing a rolling-horizon approach in project planning and management.


2014 ◽  
pp. 1521-1533
Author(s):  
Yuval Cohen ◽  
Arik Sadeh ◽  
Ofer Zwikael

Many IT projects and software development projects are very complex and sophisticated involving a large coordinated team. Such projects are a constant part of the operations of software companies such as Microsoft, SAP, Oracle, Google, Yahoo, IBM, and others. Many other companies carry large software projects as part of their IT operations. As a result of the size and complexity of such projects, a rolling horizon approach for their planning and management is not only plausible but also desirable. For large projects, traditional project scheduling techniques cannot provide an optimal and timely solution to minimum project duration under precedence and resource constraints. This paper proposes a technique that allows utilizing non-polynomial (NP) algorithms in a heuristic manner – generating high quality schedules in reasonable time. This approach can be applied efficiently for solving most project scheduling problems. The main advantage of this approach is its ability to dissect the original problem into small sub-problems of a controllable size to which exact techniques can be applied. Thus, it neutralizes the complexity of the applied algorithms (and their non-polynomial growth). Moreover, the same technique could be used for implementing a rolling-horizon approach in project planning and management.


Author(s):  
Yuval Cohen ◽  
Arik Sadeh ◽  
Ofer Zwikael

Many IT projects and software development projects are very complex and sophisticated involving a large coordinated team. Such projects are a constant part of the operations of software companies such as Microsoft, SAP, Oracle, Google, Yahoo, IBM, and others. Many other companies carry large software projects as part of their IT operations. As a result of the size and complexity of such projects, a rolling horizon approach for their planning and management is not only plausible but also desirable. For large projects, traditional project scheduling techniques cannot provide an optimal and timely solution to minimum project duration under precedence and resource constraints. This paper proposes a technique that allows utilizing non-polynomial (NP) algorithms in a heuristic manner – generating high quality schedules in reasonable time. This approach can be applied efficiently for solving most project scheduling problems. The main advantage of this approach is its ability to dissect the original problem into small sub-problems of a controllable size to which exact techniques can be applied. Thus, it neutralizes the complexity of the applied algorithms (and their non-polynomial growth). Moreover, the same technique could be used for implementing a rolling-horizon approach in project planning and management.


Author(s):  
Amir Ahrari ◽  
Ali Haghani

Two scheduling practices are commonly used depending on the availability of resources. When resources are not expensive, activities are scheduled and then resources are allocated until the available resources are exhausted. Then, iterative adjustments are applied to the resource allocation plan and the activities sequence to reach a feasible solution. Conversely, when expensive resources are involved, a resource allocation plan based on the economics of the resource is established and then activities are scheduled accordingly. However, Resource Constrained Scheduling Problems (RCSP) are not solved efficiently with either of these approaches. To find the optimal solution, activity scheduling and resource allocation should be formulated as an integrated optimization problem. Such models become numerically cumbersome for practical size problems and difficult to solve. In this article, a novel mathematical formulation and an efficient solution algorithm are proposed for solving RCSPs. Then, this framework is used for solving a practical problem in the context of the construction industry.


Author(s):  
Fereshteh Hoseini ◽  
Mostafa Ghobaei Arani ◽  
Alireza Taghizadeh

<p class="Abstract">By increasing the use of cloud services and the number of requests to processing tasks with minimum time and costs, the resource allocation and scheduling, especially in real-time applications become more challenging. The problem of resource scheduling, is one of the most important scheduling problems in the area of NP-hard problems. In this paper, we propose an efficient algorithm is proposed to schedule real-time cloud services by considering the resource constraints. The simulation results show that the proposed algorithm shorten the processing time of tasks and decrease the number of canceled tasks.</p>


2019 ◽  
Vol 29 (1) ◽  
pp. 31-42 ◽  
Author(s):  
E.Kh. Gimadi ◽  
E.N. Goncharov ◽  
D.V. Mishin

We consider a resource-constrained project scheduling problem with respect to the makespan minimization criterion. The problem accounts for technological constraints of activities precedence together with resource constraints. Activities pre- emptions are not allowed. The problem with renewable resources is NP-hard in the strong sense. We propose an exact branch and bound algorithm for solving the problem with renewable resources. It uses our new branching scheme based on the representation of a schedule in form of the activity list. We use two approaches of constructing the lower bound. We present results of numerical experiments, illustrating the quality of the proposed lower bounds. The test instances are taken from the library of test instances PSPLIB.


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