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Efficient priority rules for the resource-constrained project scheduling problem / Rainer Kolisch in Journal of operations management, Vol. 14 N°3 (Septembre 1996)  

Public ISBD [article]  inJournal of operations management > Vol. 14 N°3 (Septembre 1996) . - pp. 179–192 Titre : Efficient priority rules for the resource-constrained project scheduling problem Type de document : texte imprimé Auteurs : Rainer Kolisch, Auteur Année de publication : 2007 Article en page(s) : pp. 179–192 Note générale : Génie Industriel Langues : Anglais (eng) Mots-clés : Resource-constrained project scheduling Paraliel scheme Priority rules Single-pass heuristics Experimental evaluation Résumé : Resource-constrained project scheduling is a core problem for many industrial applications, e.g. finite scheduling systems and the planning of business re-engineering processes. In order to solve these problems commercial systems employ classical priority rules. We review one of them, the well-known RSM priority rule. A detailed analysis of this rule, reveals that it does not reflect the finite capacity of resources properly. Consequently, this leads to poor solutions. Hence, an improved RSM priority rule is derived and two new priority rules are developed which extend the well-known precedence based Minimum SLacK priority rule (MSLK) to a precedence and resource based slack priority rule, respectively. On the basis of a comprehensive experimental investigation we provide new insight into the performance of classical and new rules. Furthermore, we show that one of the new rules is significantly better than the classical rules and hence should be employed in project scheduling systems. DEWEY : 658.57 ISSN : 0272-6963 En ligne : http://www.sciencedirect.com/science/article/pii/0272696395000321 [article] Efficient priority rules for the resource-constrained project scheduling problem [texte imprimé] / Rainer Kolisch, Auteur . - 2007 . - pp. 179–192. Génie Industriel Langues : Anglais (eng) in Journal of operations management > Vol. 14 N°3 (Septembre 1996) . - pp. 179–192 Mots-clés : Resource-constrained project scheduling Paraliel scheme Priority rules Single-pass heuristics Experimental evaluation Résumé : Resource-constrained project scheduling is a core problem for many industrial applications, e.g. finite scheduling systems and the planning of business re-engineering processes. In order to solve these problems commercial systems employ classical priority rules. We review one of them, the well-known RSM priority rule. A detailed analysis of this rule, reveals that it does not reflect the finite capacity of resources properly. Consequently, this leads to poor solutions. Hence, an improved RSM priority rule is derived and two new priority rules are developed which extend the well-known precedence based Minimum SLacK priority rule (MSLK) to a precedence and resource based slack priority rule, respectively. On the basis of a comprehensive experimental investigation we provide new insight into the performance of classical and new rules. Furthermore, we show that one of the new rules is significantly better than the classical rules and hence should be employed in project scheduling systems. DEWEY : 658.57 ISSN : 0272-6963 En ligne : http://www.sciencedirect.com/science/article/pii/0272696395000321

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An iterative local constraints based analysis for solving the resource constrained project scheduling problem / Linet Özdamar in Journal of operations management, Vol. 14 N°3 (Septembre 1996)  

Public ISBD [article]  inJournal of operations management > Vol. 14 N°3 (Septembre 1996) . - pp. 193–208 Titre : An iterative local constraints based analysis for solving the resource constrained project scheduling problem Type de document : texte imprimé Auteurs : Linet Özdamar, Auteur ; Gündüz Ulusoy, Auteur Année de publication : 2007 Article en page(s) : pp. 193–208 Note générale : Génie Industriel Langues : Anglais (eng) Mots-clés : Project management-resource constraints Heuristic Multiple criteria Résumé : In this paper, a new heuristic iterative scheduling approach is proposed for the resource constrained project scheduling problem. Well-known dispatching rules and a decision-making process called Local Constraint Based Analysis (LCBA), previously tested in a single pass forward parallel scheduling algorithm, are imbedded in the iterative scheduling algorithm. LCBA evaluates and selects the activities competing for scarce resources by considering the currently active temporal and resource constraints imposed by the network/resource characteristics. The iterative scheduling algorithm proposed here makes consecutive forward/backward scheduling passes which improve the project duration obtained by the single forward scheduling pass. Extensive experimentation has been done on a set of 188 benchmark problems from the literature. The results demonstrate that all the methods imbedded in the iterative algorithm improved the project duration significantly. It is observed that LCBA's average project duration deviation from the optimal duration is of the magnitude of 1% using the iterative scheduling algorithm. Among all the methods which have been tested, LCBA and a list rule, Weighted Resource Utilization and Precedence (WRUP), are the ones which have benefited most from the iterative algorithm. It is also observed that for various cash flow schemes the project Net Present Value (NPV) is improved through the use of the iterative scheduling algorithm. DEWEY : 658.57 ISSN : 0272-6963 En ligne : http://www.sciencedirect.com/science/article/pii/0272696395000151 [article] An iterative local constraints based analysis for solving the resource constrained project scheduling problem [texte imprimé] / Linet Özdamar, Auteur ; Gündüz Ulusoy, Auteur . - 2007 . - pp. 193–208. Génie Industriel Langues : Anglais (eng) in Journal of operations management > Vol. 14 N°3 (Septembre 1996) . - pp. 193–208 Mots-clés : Project management-resource constraints Heuristic Multiple criteria Résumé : In this paper, a new heuristic iterative scheduling approach is proposed for the resource constrained project scheduling problem. Well-known dispatching rules and a decision-making process called Local Constraint Based Analysis (LCBA), previously tested in a single pass forward parallel scheduling algorithm, are imbedded in the iterative scheduling algorithm. LCBA evaluates and selects the activities competing for scarce resources by considering the currently active temporal and resource constraints imposed by the network/resource characteristics. The iterative scheduling algorithm proposed here makes consecutive forward/backward scheduling passes which improve the project duration obtained by the single forward scheduling pass. Extensive experimentation has been done on a set of 188 benchmark problems from the literature. The results demonstrate that all the methods imbedded in the iterative algorithm improved the project duration significantly. It is observed that LCBA's average project duration deviation from the optimal duration is of the magnitude of 1% using the iterative scheduling algorithm. Among all the methods which have been tested, LCBA and a list rule, Weighted Resource Utilization and Precedence (WRUP), are the ones which have benefited most from the iterative algorithm. It is also observed that for various cash flow schemes the project Net Present Value (NPV) is improved through the use of the iterative scheduling algorithm. DEWEY : 658.57 ISSN : 0272-6963 En ligne : http://www.sciencedirect.com/science/article/pii/0272696395000151

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The development of cash flow weight procedures for maximizing the net present value of a project / Sami M. Baroum in Journal of operations management, Vol. 14 N°3 (Septembre 1996)  

Public ISBD [article]  inJournal of operations management > Vol. 14 N°3 (Septembre 1996) . - pp. 209–227 Titre : The development of cash flow weight procedures for maximizing the net present value of a project Type de document : texte imprimé Auteurs : Sami M. Baroum, Auteur ; James H. Patterson, Auteur Année de publication : 2007 Article en page(s) : pp. 209–227 Note générale : Génie Industriel Langues : Anglais (eng) Mots-clés : Cash flow weight Heuristic procedures Résumé : We describe in this paper the development of heuristic procedures for obtaining improved solutions to the maximize ion of net present value in a network problem. Optimization techniques have not been successful in solving this limited resource problem for large projects. As a result, rule-of-thumb heuristic approaches have historically been used to improve the financial returns from project activity. The heuristic procedures we describe assign weights to activities based upon the cumulative cash flows for the activity and all of its logical successors. Subsequent application of multi-pass shifting algorithms search locally for improved activity assignments, resulting in increased project net present value over the initial solution obtained. Results reported demonstrate the efficacy of this approach over more traditional methods for solving this problem. We also contrast the cash flow weighting heuristics developed with other implementations of cash flow weighting procedures. Despite their inherent simplicity, the procedures described quite often produce improved results over other approaches when maximum net present value solutions are desired. DEWEY : 658.57 ISSN : 0272-6963 En ligne : http://www.sciencedirect.com/science/article/pii/0272696396000058 [article] The development of cash flow weight procedures for maximizing the net present value of a project [texte imprimé] / Sami M. Baroum, Auteur ; James H. Patterson, Auteur . - 2007 . - pp. 209–227. Génie Industriel Langues : Anglais (eng) in Journal of operations management > Vol. 14 N°3 (Septembre 1996) . - pp. 209–227 Mots-clés : Cash flow weight Heuristic procedures Résumé : We describe in this paper the development of heuristic procedures for obtaining improved solutions to the maximize ion of net present value in a network problem. Optimization techniques have not been successful in solving this limited resource problem for large projects. As a result, rule-of-thumb heuristic approaches have historically been used to improve the financial returns from project activity. The heuristic procedures we describe assign weights to activities based upon the cumulative cash flows for the activity and all of its logical successors. Subsequent application of multi-pass shifting algorithms search locally for improved activity assignments, resulting in increased project net present value over the initial solution obtained. Results reported demonstrate the efficacy of this approach over more traditional methods for solving this problem. We also contrast the cash flow weighting heuristics developed with other implementations of cash flow weighting procedures. Despite their inherent simplicity, the procedures described quite often produce improved results over other approaches when maximum net present value solutions are desired. DEWEY : 658.57 ISSN : 0272-6963 En ligne : http://www.sciencedirect.com/science/article/pii/0272696396000058

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Using discounted cash flow heuristics to improve project net present valve / Jonathan P. Pinder in Journal of operations management, Vol. 14 N°3 (Septembre 1996)  

Public ISBD [article]  inJournal of operations management > Vol. 14 N°3 (Septembre 1996) . - pp. 229–240 Titre : Using discounted cash flow heuristics to improve project net present valve Type de document : texte imprimé Auteurs : Jonathan P. Pinder, Auteur ; Ann S. Marucheck, Auteur Année de publication : 2007 Article en page(s) : pp. 229–240 Note générale : Génie Industriel Langues : Anglais (eng) Mots-clés : Project management Scheduling Heuristics Net present value Résumé : The problem of scheduling resource-constrained projects to maximize their Net Present Value (NPV) is studied in this paper. The performance of seventeen scheduling heuristics, ten of which are original to this work, is evaluated. Heuristic performance is rated separately on maximization of project NPV and minimization of project duration. Two of the new heuristics are significantly better than the standard heuristics at yielding higher project NPVs. These two heuristics also perform well at reducing project duration. Two heuristics, Minslack and Shortest Processing Time (SPT), that performed well in previous studies are shown to be poor performers at maximizing project NPV. DEWEY : 658.57 ISSN : 0272-6963 En ligne : http://www.sciencedirect.com/science/article/pii/0272696396000034 [article] Using discounted cash flow heuristics to improve project net present valve [texte imprimé] / Jonathan P. Pinder, Auteur ; Ann S. Marucheck, Auteur . - 2007 . - pp. 229–240. Génie Industriel Langues : Anglais (eng) in Journal of operations management > Vol. 14 N°3 (Septembre 1996) . - pp. 229–240 Mots-clés : Project management Scheduling Heuristics Net present value Résumé : The problem of scheduling resource-constrained projects to maximize their Net Present Value (NPV) is studied in this paper. The performance of seventeen scheduling heuristics, ten of which are original to this work, is evaluated. Heuristic performance is rated separately on maximization of project NPV and minimization of project duration. Two of the new heuristics are significantly better than the standard heuristics at yielding higher project NPVs. These two heuristics also perform well at reducing project duration. Two heuristics, Minslack and Shortest Processing Time (SPT), that performed well in previous studies are shown to be poor performers at maximizing project NPV. DEWEY : 658.57 ISSN : 0272-6963 En ligne : http://www.sciencedirect.com/science/article/pii/0272696396000034

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Heuristic scheduling of capital constrained projects / Dwight E. Smith-Daniels in Journal of operations management, Vol. 14 N°3 (Septembre 1996)  

Public ISBD [article]  inJournal of operations management > Vol. 14 N°3 (Septembre 1996) . - pp. 241–254 Titre : Heuristic scheduling of capital constrained projects Type de document : texte imprimé Auteurs : Dwight E. Smith-Daniels, Auteur ; Rema Padman, Auteur ; Vicki L. Smith-Daniels, Auteur Année de publication : 2007 Article en page(s) : pp. 241–254 Note générale : Génie Industriel Langues : Anglais (eng) Mots-clés : Heuristic scheduling Constrained projects Résumé : The movement to product and process development projects that involve joint ventures among strategic partners, as well as the increasing prevalence of projects within organizations has led to increased implementation of project scheduling methods. It is frequently the case that a capital constraint is placed on a project, thus limiting the number and value of activities that can be scheduled to occur simultaneously. However, the quantity of capital available to schedule activities can increase as additional cash is received as progress payments for completed activities. Since the project manager'so objective is to maximize project Net Present Value (NPV), it is important for the manager to develop a schedule that balances the early receipt of progress payments (which improve NPV and increase the capital balance available), with the delay of particularly large expenditures. Due to the intractability of optimal methods, the use of heuristic methods is required to solve problems of practical size. This paper presents the first test of heuristic methods for solving this problem. We use information from a relaxed optimization-guided model that employs information from the unconstrained NPV-optimal problem in heuristic procedure for solving the capital constrained problem. An experimental design is employed to test the heuristics that includes multiple factor levels for a number of project characteristics, including capital utilization, frequency of progress payments, and project network structure. The results indicate very good relative performance for the optimization-guided procedures as compared to two benchmark heuristics. DEWEY : 658.57 ISSN : 0272-6963 En ligne : http://www.sciencedirect.com/science/article/pii/0272696396000046 [article] Heuristic scheduling of capital constrained projects [texte imprimé] / Dwight E. Smith-Daniels, Auteur ; Rema Padman, Auteur ; Vicki L. Smith-Daniels, Auteur . - 2007 . - pp. 241–254. Génie Industriel Langues : Anglais (eng) in Journal of operations management > Vol. 14 N°3 (Septembre 1996) . - pp. 241–254 Mots-clés : Heuristic scheduling Constrained projects Résumé : The movement to product and process development projects that involve joint ventures among strategic partners, as well as the increasing prevalence of projects within organizations has led to increased implementation of project scheduling methods. It is frequently the case that a capital constraint is placed on a project, thus limiting the number and value of activities that can be scheduled to occur simultaneously. However, the quantity of capital available to schedule activities can increase as additional cash is received as progress payments for completed activities. Since the project manager'so objective is to maximize project Net Present Value (NPV), it is important for the manager to develop a schedule that balances the early receipt of progress payments (which improve NPV and increase the capital balance available), with the delay of particularly large expenditures. Due to the intractability of optimal methods, the use of heuristic methods is required to solve problems of practical size. This paper presents the first test of heuristic methods for solving this problem. We use information from a relaxed optimization-guided model that employs information from the unconstrained NPV-optimal problem in heuristic procedure for solving the capital constrained problem. An experimental design is employed to test the heuristics that includes multiple factor levels for a number of project characteristics, including capital utilization, frequency of progress payments, and project network structure. The results indicate very good relative performance for the optimization-guided procedures as compared to two benchmark heuristics. DEWEY : 658.57 ISSN : 0272-6963 En ligne : http://www.sciencedirect.com/science/article/pii/0272696396000046

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The resource constrained time/cost tradeoff project scheduling problem with discounted cash flows / Oya Icmeli in Journal of operations management, Vol. 14 N°3 (Septembre 1996)  

Public ISBD [article]  inJournal of operations management > Vol. 14 N°3 (Septembre 1996) . - pp. 255–275 Titre : The resource constrained time/cost tradeoff project scheduling problem with discounted cash flows Type de document : texte imprimé Auteurs : Oya Icmeli, Auteur ; S.Selcuk Erenguc, Auteur Année de publication : 2007 Article en page(s) : pp. 255–275 Note générale : Génie Industriel Langues : Anglais (eng) Mots-clés : Time/cost tradeoff project scheduling Cash flows Résumé : Many of the recent studies on Project Scheduling focus on maximizing the Net Present Value (NPV) of cash flows that occur during the implementation of a project in the presence of precedence and resource constraints. The literature contains several integer programming formulations, heuristic procedures and their implementations. In most of these formulations, activity durations are assumed to be fixed. In this paper, we study a practical extension of the problem where the activity durations can be reduced from their normal durations by allocating more resources. Costs associated with such reductions are referred to as crashing costs. The problem under consideration involves determining the timing and duration of activities such that the NPV of all cash flows is maximized in the presence of precedence and resource constraints. We suggest a heuristic procedure for obtaining “good” feasible solutions. We compare the performance of three priority rules embedded in the proposed procedure. Two of these priority rules have been shown to be the most effective in the literature, the third is a new rule developed in this paper. Extensive computational experiments with the heuristic procedure on a total of 380 test problems are reported. The heuristic solutions are compared to benchmark solutions obtained from the best of 50-randomly generated solutions for each test problem. In addition, upper bounds on the optimal values are obtained by performing Subgradient optimization on a Lagrangian Relaxation of the problem. These upper bounds are used to assess the quality of the heuristic solutions. In general, none of the priority rules produced consistently better results for all the test problems. However, all three priority rules provide “good” quality solutions with modest computational effort. The Lagrangian approach is found to provide tight bounds on the optimal values. DEWEY : 658.57 ISSN : 0272-6963 En ligne : http://www.sciencedirect.com/science/article/pii/0272696395000259 [article] The resource constrained time/cost tradeoff project scheduling problem with discounted cash flows [texte imprimé] / Oya Icmeli, Auteur ; S.Selcuk Erenguc, Auteur . - 2007 . - pp. 255–275. Génie Industriel Langues : Anglais (eng) in Journal of operations management > Vol. 14 N°3 (Septembre 1996) . - pp. 255–275 Mots-clés : Time/cost tradeoff project scheduling Cash flows Résumé : Many of the recent studies on Project Scheduling focus on maximizing the Net Present Value (NPV) of cash flows that occur during the implementation of a project in the presence of precedence and resource constraints. The literature contains several integer programming formulations, heuristic procedures and their implementations. In most of these formulations, activity durations are assumed to be fixed. In this paper, we study a practical extension of the problem where the activity durations can be reduced from their normal durations by allocating more resources. Costs associated with such reductions are referred to as crashing costs. The problem under consideration involves determining the timing and duration of activities such that the NPV of all cash flows is maximized in the presence of precedence and resource constraints. We suggest a heuristic procedure for obtaining “good” feasible solutions. We compare the performance of three priority rules embedded in the proposed procedure. Two of these priority rules have been shown to be the most effective in the literature, the third is a new rule developed in this paper. Extensive computational experiments with the heuristic procedure on a total of 380 test problems are reported. The heuristic solutions are compared to benchmark solutions obtained from the best of 50-randomly generated solutions for each test problem. In addition, upper bounds on the optimal values are obtained by performing Subgradient optimization on a Lagrangian Relaxation of the problem. These upper bounds are used to assess the quality of the heuristic solutions. In general, none of the priority rules produced consistently better results for all the test problems. However, all three priority rules provide “good” quality solutions with modest computational effort. The Lagrangian approach is found to provide tight bounds on the optimal values. DEWEY : 658.57 ISSN : 0272-6963 En ligne : http://www.sciencedirect.com/science/article/pii/0272696395000259

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A study of approximating the moments of the job completion time in PERT networks / Kishan Mehrotra in Journal of operations management, Vol. 14 N°3 (Septembre 1996)  

Public ISBD [article]  inJournal of operations management > Vol. 14 N°3 (Septembre 1996) . - pp. 277–289 Titre : A study of approximating the moments of the job completion time in PERT networks Type de document : texte imprimé Auteurs : Kishan Mehrotra, Auteur ; John Chai, Auteur ; Sharma Pillutla, Auteur Année de publication : 2007 Article en page(s) : pp. 277–289 Note générale : Génie Industriel Langues : Anglais (eng) Mots-clés : CPM (Critical Path Method) PERT (Program Evaluation Review technique) TCJ (Time to complete the Job) Node Arc AOA (Activity-on-Arrow) Deterministic Stochastic activity index Activity critically Critical path Subcritical L.i.d. (independent and identically distributed) Résumé : The importance of proper management of projects has not gone unrecognized in industry and academia. Consequently, tools like the Critical Path Method (CPM) and the Program Evaluation Review Technique (PERT) for project planning have been the focus of attention of both practitioners and researchers. Determination of the Time to Complete the Job (TCJ) in PERT networks is important for planning and bidding purposes. The complexity involved in accurately determining the TCJ has led to the development of many approximating procedures. Most of them ignore the dependence between paths in the network. We propose an approximation to determine the TCJ which explicitly recognizes this dependency. Dependency in networks arises due to commonality of activities among various paths in the network. We develop an approximation which is simple to use and makes use of readily available tables. Also, the approximation employs the traditional concept of the critical path which is easy to understand and to operationalize. The activities on the critical paths are divided into an independent portion and a dependent portion. The dependent portion comprises activities common to various critical paths. Order statistics are used in computing the time for the dependent portion of the critical path. We present the theoretical underpinnings of our approach and illustrate its application via an example. In the absence of other measures, we use simulation results as a proxy for the TCJ and as a benchmark to measure the accuracy of our approximation. Empirical results are obtained for a variety of networks in the literature. We show that the distribution of the TCJ is better approximated by a mixture of distributions. Comparison with other approaches from the literature indicates that our approximation yields estimates for the TCJ which are closer to the simulation results. DEWEY : 658.57 ISSN : 0272-6963 En ligne : http://www.sciencedirect.com/science/article/pii/0272696396000022 [article] A study of approximating the moments of the job completion time in PERT networks [texte imprimé] / Kishan Mehrotra, Auteur ; John Chai, Auteur ; Sharma Pillutla, Auteur . - 2007 . - pp. 277–289. Génie Industriel Langues : Anglais (eng) in Journal of operations management > Vol. 14 N°3 (Septembre 1996) . - pp. 277–289 Mots-clés : CPM (Critical Path Method) PERT (Program Evaluation Review technique) TCJ (Time to complete the Job) Node Arc AOA (Activity-on-Arrow) Deterministic Stochastic activity index Activity critically Critical path Subcritical L.i.d. (independent and identically distributed) Résumé : The importance of proper management of projects has not gone unrecognized in industry and academia. Consequently, tools like the Critical Path Method (CPM) and the Program Evaluation Review Technique (PERT) for project planning have been the focus of attention of both practitioners and researchers. Determination of the Time to Complete the Job (TCJ) in PERT networks is important for planning and bidding purposes. The complexity involved in accurately determining the TCJ has led to the development of many approximating procedures. Most of them ignore the dependence between paths in the network. We propose an approximation to determine the TCJ which explicitly recognizes this dependency. Dependency in networks arises due to commonality of activities among various paths in the network. We develop an approximation which is simple to use and makes use of readily available tables. Also, the approximation employs the traditional concept of the critical path which is easy to understand and to operationalize. The activities on the critical paths are divided into an independent portion and a dependent portion. The dependent portion comprises activities common to various critical paths. Order statistics are used in computing the time for the dependent portion of the critical path. We present the theoretical underpinnings of our approach and illustrate its application via an example. In the absence of other measures, we use simulation results as a proxy for the TCJ and as a benchmark to measure the accuracy of our approximation. Empirical results are obtained for a variety of networks in the literature. We show that the distribution of the TCJ is better approximated by a mixture of distributions. Comparison with other approaches from the literature indicates that our approximation yields estimates for the TCJ which are closer to the simulation results. DEWEY : 658.57 ISSN : 0272-6963 En ligne : http://www.sciencedirect.com/science/article/pii/0272696396000022

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