Sharif Digital Repository

The purpose of this paper is to present a polynomial time algorithm which determines the lot sizes for purchase component in Material Requirement Planning (MRP) environments with deterministic time-phased demand with zero lead time. In this model, backlog is not permitted, the unit purchasing price is based on the all-units discount system and resale of the excess units is possible at the ordering time. The properties of an optimal order policy are argued and on the basis of them, a branch and bound algorithm is presented to construct an optimal sequence of order policies. In the proposed B&B algorithm, some useful fathoming rules have been proven to make the algorithm very efficient. By... 

This paper considers a project scheduling problem with the objective of minimizing resource availability costs required to execute the activities in a project by a given project deadline. The project contains activities interrelated by finish-start-type precedence relations with a time lag of zero, which require a set of renewable resources. Two metaheuristics, path relinking and genetic algorithm, are developed to tackle this problem in which a schedule is created with a precedence feasible priority list given to the schedule generation scheme. In these procedures, each new generation of solutions are created using the combination of current solutions. Comparative computational results... 

The literature suggests that organizations cannot be competitive if their business and information technology strategies are not aligned. Yet achieving strategic alignment continues to be a major concern for business executives. A number of alignment models have been offered in the literature, primary among them the Strategic Alignment model (SAM) and IT Governance (via ITIL). As there is no published research that attempts to present how effective ITIL V3 is to align business and IT in strategic level, this paper reports on determining aligning roles of ITIL by applying it to the SAM framework. In this regard, the (TIL Strategic Alignment model is proposed to describe ITIL V3 approach of... 

Ensuring that organizational IT is in alignment with and provides support for an organization's business strategy is critical to business success. As there is no published research that attempts to describe maturity of ITIL V3 in aligning business and IT at strategic level, this paper reports on determining aligning roles of ITIL V3 in practice. In this paper, ITIL maturity to business-IT strategic alignment is validated by Strategic Alignment Maturity model. Focusing on how ITIL V3 covers business-IT alignment maturity criteria of the model, the maturity of ITIL strategic alignment practices is assessed which makes it possible to recognize conceptual and practical competencies of ITIL to... 

The literature suggests that organizations cannot be competitive if their business and information technology strategies are not aligned. Yet achieving strategic alignment continues to be a major concern for business executives. A number of alignment models have been offered in the literature, primary among them the Strategic Alignment model (SAM) and IT Governance (via ITIL). As there is no published research that attempts to present how effective ITIL V3 is to align business and IT in strategic level, this paper reports on determining aligning roles of ITIL by applying it to the SAM framework. In this regard, the ITIL Strategic Alignment model is proposed to describe ITIL V3 approach of... 

Purpose: The aim of this research is to propose a buffer sizing and buffer controlling algorithm (BSCA) as a heuristic algorithm for calculating project buffer and feeding buffers as well as dynamic controlling of buffer consumption in different phases of a wind power plant project in order to achieve a more realistic project duration. Design/methodology/approach: The BSCA algorithm has two main phases of planning and buffer sizing and construction and buffer consumption. Project buffer and feeding buffers are determined in the planning and buffer sizing phase, and their consumption is controlled in the construction and buffer consumption phase. The heuristic algorithm was coded and run in... 

One of the major problems with projects is that they are not completed according to schedule. Uncertainty always exists at the heart of real-world project scheduling problems. This paper introduces a fuzzy project buffer management (FPBM) algorithm which is a combination of the adaptive procedure with resource tightness (APRT) and fuzzy failure mode and effects analysis (FFMEA) methods. This paper aims to present an efficient model for project buffer sizing by taking FFMEA into account to reach a more realistic schedule. In this research, for increasing the efficiency of the APRT method, the FFMEA technique is simultaneously applied with them. This research was carried out as a case study in... 

One of the major problems with projects is that they are not completed according to schedule. Uncertainty always exists at the heart of real-world project scheduling problems. This paper introduces a fuzzy project buffer management (FPBM) algorithm which is a combination of the adaptive procedure with resource tightness (APRT) and fuzzy failure mode and effects analysis (FFMEA) methods. This paper aims to present an efficient model for project buffer sizing by taking FFMEA into account to reach a more realistic schedule. In this research, for increasing the efficiency of the APRT method, the FFMEA technique is simultaneously applied with them. This research was carried out as a case study in... 

When the number of projects in a company increases, it becomes very important to choose the right strategy to supply resources and raw materials in profit and loss and finish the work according to the schedule. This study presents a new mathematical model using the fractal method to optimize the resource planning system in project-oriented construction and industrial companies, and the results are analyzed. This article aims to introduce a fractal resource requirement planning (FRRP) model in project-oriented construction and industrial companies by providing a fractal framework to minimize resource costs and the smooth flow of materials between projects to meet the existing demand. Assuming... 

We introduce a multimode resource-constrained project scheduling problem with finish-to-start precedence relations among project activities, considering renewable and nonrenewable resource costs. We assume that renewable resources are rented and are not available in all periods of time of the project. In other words, there is a mandated ready date as well as a due date for each renewable resource type so that no resource is used before its ready date. However, the resources are permitted to be used after their due dates by paying penalty costs. The objective is to minimize the total costs of both renewable and nonrenewable resource usage. This problem is called multimode resource-constrained... 

In this paper a genetic algorithm for solving a class of project scheduling problems, called Resource Investment Problem, is presented. Tardiness of project is permitted with defined penalty. Elements of algorithm such as chromosome structure, unfitness function, crossover, mutation, immigration and local search operations are explained. The performance of this genetic algorithm is compared with the performance of other published algorithms for Resource Investment Problem. Also 690 problems are solved and their optimal solutions are used for the performance tests of the genetic algorithm. The tests results are quite satisfactory. © 2006 Elsevier B.V. All rights reserved  

In this paper, a genetic algorithm for solving a class of project scheduling problems, called Resource Investment Problems, is presented. Tardiness of the project is permitted with a defined penalty. The decision variables are the level of resources and the start times of the activities. The objective is to minimize the sum of resources and delay penalty costs, subject to the activities' precedence relations and some other constraints. A revised form of the Akpan heuristic method for this problem is used to find better chromosomes. Elements of the algorithm, such as chromosome structure, unfitness function, crossover, mutation, immigration and local search operations, are explained. The...