Multi-Project Scheduling and Control: A Process-Based Comparative Study of the Critical Chain Methodology and Some Alternatives

2004 ◽  
Vol 35 (2) ◽  
pp. 39-50 ◽  
Author(s):  
Izack Cohen ◽  
Avishai Mandelbaum ◽  
Avraham Shtub
2018 ◽  
Vol 06 (02) ◽  
pp. 95-118 ◽  
Author(s):  
Mohammadreza Radmanesh ◽  
Manish Kumar ◽  
Paul H. Guentert ◽  
Mohammad Sarim

Unmanned aerial vehicles (UAVs) have recently attracted the attention of researchers due to their numerous potential civilian applications. However, current robot navigation technologies need further development for efficient application to various scenarios. One key issue is the “Sense and Avoid” capability, currently of immense interest to researchers. Such a capability is required for safe operation of UAVs in civilian domain. For autonomous decision making and control of UAVs, several path-planning and navigation algorithms have been proposed. This is a challenging task to be carried out in a 3D environment, especially while accounting for sensor noise, uncertainties in operating conditions, and real-time applicability. Heuristic and non-heuristic or exact techniques are the two solution methodologies that categorize path-planning algorithms. The aim of this paper is to carry out a comprehensive and comparative study of existing UAV path-planning algorithms for both methods. Three different obstacle scenarios test the performance of each algorithm. We have compared the computational time and solution optimality, and tested each algorithm with variations in the availability of global and local obstacle information.


2021 ◽  
Vol 10 (5) ◽  
pp. 2549-2559
Author(s):  
K.R. Kumar ◽  
E.N. Satheesh ◽  
V.R. Pravitha

Kerala, a southern state of India, has shown better performance in the initial months of the spread of the disease. But in the last few months, the spread of the disease in the state has grown breaking all controls and the control and management system has shown very poor performance. Mathematical modeling of the spread of the disease is effectively is being used in the prediction and control of the disease world over. In this paper, we make a comparative study of the research conducted on this subject based on the compartmental models and social network analysis based models giving special emphasis to Kerala state. We also point out the drawbacks of the current studies in comparison with the intensity of the actual spread of disease.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Tarek Salama ◽  
Ahmad Salah ◽  
Osama Moselhi

Purpose The purpose of this paper is to present a new method for project tracking and control of integrated offsite and onsite activities in modular construction considering practical characteristics associated with this type of construction. Design/methodology/approach The design embraces building information modelling and integrates last planner system (LPS), linear scheduling method (LSM) and critical chain project management (CCPM) to develop tracking and control procedures for modular construction projects. The developed method accounts for constraints of resources continuity and uncertainties associated with activity duration. Features of proposed method are illustrated in a case example for tracking and control of modular projects. Findings Comparison between developed schedule and Monte Carlo simulation showed that baseline duration generated from simulation exceeds that produced by developed method by 12% and 10% for schedules with 50% and 90% confidence level, respectively. These percentages decrease based on interventions of members of project team in the LPS sessions. The case example results indicate that project is delayed 5% and experienced cost overrun of 2.5%. Originality/value Developed method integrated LPS, LSM and CCPM while using metrics for reliability assessment of linear schedules, namely, critical percent plan complete (PPCcr) and buffer index (BI). PPCcr and BI measure percentage of plan completion for critical activities and buffer consumption, respectively. The developed method provides a systematic procedure for forecasting look-ahead schedules using forecasting correction factor Δt and a newly developed tracking and control procedure that uses PPCcr and BI. Quantitative cost analysis is also provided to forecast and monitor project costs to prove the robustness of proposed framework.


2002 ◽  
Vol 33 (4) ◽  
pp. 48-60 ◽  
Author(s):  
Willy Herroelen ◽  
Roel Leus ◽  
Erik Demeulemeester

Critical chain scheduling/Buffer management (CCS/BM)—the direct application of the theory of constraints (TOC) to project management—has received much attention in project management literature. There still is controversy over the merits and pitfalls of the CCS/BM methodology. This paper focuses on the fundamental elements of CCS/BM logic and pinpoints some intricacies that are not commonly referred to in the available literature. The authors’ analysis is based on a critical review of the relevant sources and experimentation with both commercial CCS/BM software and an internally developed CCS/BM-based tool.


1939 ◽  
Vol 96 (3) ◽  
pp. 681-688 ◽  
Author(s):  
J. NOTKIN ◽  
C. E. NILES ◽  
F. J. DENATALE ◽  
G. WITTMAN

Robotica ◽  
2005 ◽  
Vol 24 (2) ◽  
pp. 229-237 ◽  
Author(s):  
Jae H. Chung ◽  
Changhoon Kim

This paper discusses the modeling and control of a robotic manipulator with a new deburring tool, which integrates two pneumatic actuators to take advantage of a double cutting action. A coordination control method is developed by decomposing the robotic deburring system into two subsystems; the arm and the deburring tool. A decentralized control approach is pursued, in which suitable controllers were designed for the two subsystems in the coordination scheme. In simulation, three different tool configurations are considered: rigid, single pneumatic and integrated pneumatic tools. A comparative study is performed to investigate the deburring performance of the deburring arm with the different tools. Simulation results show that the developed robotic deburring system significantly improves the accuracy of the deburring operation.


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