Dynamic scheduling model for the construction industry

2019 ◽  
Vol 10 (3) ◽  
pp. 313-330
Author(s):  
Amer Fahmy ◽  
Tarek Hassan ◽  
Hesham Bassioni ◽  
Ronald McCaffer
Keyword(s):  
Real Time ◽  
Cost Efficiency ◽  
Dynamic Scheduling ◽  
Real Life ◽  
Content Type ◽  
Resources Management ◽  
Real Time Scheduling ◽  
Time Scheduling ◽  
Labor Utilization

Purpose Basic project control through traditional methods is not sufficient to manage the majority of real-time events in most construction projects. The purpose of this paper is to propose a Dynamic Scheduling (DS) model that utilizes multi-objective optimization of cost, time, resources and cash flow, throughout project construction. Design/methodology/approach Upon reviewing the topic of DS, a worldwide internet survey with 364 respondents was conducted to define end-user requirements. The model was formulated and solution algorithms discussed. Verification was reported using predefined problem sets and a real-life case. Validation was performed via feedback from industry experts. Findings The need for multi-objective dynamic software optimization of construction schedules and the ability to choose among a set of optimal alternatives were highlighted. Model verification through well-known test cases and a real-life project case study showed that the model successfully achieved the required dynamic functionality whether under the small solved example or under the complex case study. The model was validated for practicality, optimization of various DS schedule quality gates, ease of use and software integration with contemporary project management practices. Practical implications Optimized real-time scheduling can provide better resources management including labor utilization and cost efficiency. Furthermore, DS contributes to optimum materials procurement, thus minimizing waste. Social implications Optimized real-time scheduling can provide better resources management including labor utilization and cost efficiency. Furthermore, DS contributes to optimum materials procurement, thus minimizing waste. Originality/value The paper illustrates the importance of DS in construction, identifies the user needs and overviews the development, verification and validation of a model that supports the generation of high-quality schedules beneficial to large-scale projects.

scholarly journals Dynamic Soft Real-Time Scheduling with Preemption Threshold for Streaming Media

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Wenle Wang ◽  
Yuan Wang ◽  
JiangYan Dai ◽  
Zhonghua Cao
Keyword(s):  
Real Time ◽  
Video Streaming ◽  
Dynamic Scheduling ◽  
Threshold Strategy ◽  
Real Time Scheduling ◽  
Time Scheduling ◽  
Simulation Results ◽  
Relationship Of ◽  
Networking Technology ◽  
Efficient Video

Over the last decades, the advancements in networking technology and new multimedia devices have motivated the research on efficient video streaming mechanisms under wireless. We consider combing soft real-time video streaming scheduling with threshold to minimize the ineffective preemption. Based on the value density and urgency of soft real-time task, the dynamic scheduling with preemption threshold strategy (DSPT) is proposed in the paper. By analyzing the response time and preemption relationship of tasks, the preemption thresholds are assigned. Simulation results show that the DSPT strategy achieves improvements about success rate, delay time, and benefit of the system.

A Real-Time Scheduling Algorithm Based on Priority Table

2013 ◽  
Vol 756-759 ◽  
pp. 3929-3936
Author(s):  
Er Feng Su ◽  
Kai Long Zhang ◽  
Xing She Zhou ◽  
Chen Fan
Keyword(s):  
Real Time ◽  
Dynamic Scheduling ◽  
Heuristic Algorithms ◽  
Scheduling Algorithm ◽  
Task Type ◽  
Real Time Scheduling ◽  
Success Ratio ◽  
Time Scheduling ◽  
Definition Of ◽  
Priority Table

Among preemptive real-time uniprocessor scheduling algorithms, many researches, such as optimal and heuristic algorithms, considers only one task attribute and neglects also the variation of attributes. To understand the relations between task attributes and scheduling success ratio, we first define the sensitivity of scheduling success ratio to task attributes. Sensitivity means the intensity of variation of scheduling success ratio as task attributes varies. The paper analyzes the sensitivities of scheduling success ratio to arrival time, execution time, deadline and laxity respectively, which have close relations with scheduling. Based on the definition of sensitivity, we also define attributes influence on scheduling success ratio, which is that the greater the influence, the higher the ratio. The essence of dynamic scheduling is a scheduling based on priority, with each dynamic algorithm matching a priority table, and vice versa. It is also much easier to infer the algorithm from the priority table, which can consider several task attributes. As priority table has various designs, it can correspond to a lot of algorithms, among which, many are inefficient. In order to deal with this kind of problem, we propose a new priority table design PTBM combining deadline and laxity based on the analysis of sensitivity and influence, which makes that a task with small deadline and large laxity has higher priority. We compare PTBM with EDF, LLF and PTD through simulation. The results verify the analysis of sensitivity and influence, and it also shows that PTBM outperforms on scheduling success ratio. It needs further exploration to design more efficient priority table by analyzing more task attributes influence on scheduling success ratio, which includes criticalness, task type and so on.

scholarly journals Genealogy of hard real-time preemptive scheduling algorithms for identical multiprocessors

2011 ◽  
Vol 1 (3) ◽  
Author(s):  
Dirk Müller ◽  
Matthias Werner
Keyword(s):  
Real Time ◽  
Dynamic Scheduling ◽  
Scheduling Algorithms ◽  
Real Time Scheduling ◽  
Context Switching ◽  
Migration Dynamics ◽  
Time Scheduling ◽  
And Migration ◽  
Hard Real Time ◽  
Full Utilization

AbstractWith the advent of multi-core computer systems, real-time (RT) scheduling on multiprocessors (MPs) is gaining more and more practical relevance. Basic algorithms developed in the 1970s or earlier are strongly influential on state-of-the-art preemptive hard real-time scheduling algorithms. These relationships will be revealed and visualized by four genealogies. Here, the two classification dimensions prioritization dynamics and migration dynamics serve as a framework for the systematization. Finally, such genealogical reconstructions could even lead to the discovery of new algorithms. An extra look will be devoted to the group of fully dynamic scheduling algorithms with full migration in which algorithms can reach full utilization, neglecting scheduling and context switching overheads. The important question for a set of RT scheduling algorithms serving as a basis for more sophisticated ones will be dealt with.

scholarly journals Automated Scheduling Approach under Smart Contract for Remote Wind Farms with Power-to-Gas Systems in Multiple Energy Markets

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6781
Author(s):  
Zhenya Ji ◽  
Zishan Guo ◽  
Hao Li ◽  
Qi Wang
Keyword(s):  
Real Time ◽  
Linear Model ◽  
Wind Farms ◽  
Energy Markets ◽  
Smart Contracts ◽  
Real Time Scheduling ◽  
Smart Contract ◽  
Time Scheduling ◽  
Power To Gas

The promising power-to-gas (P2G) technology makes it possible for wind farms to absorb carbon and trade in multiple energy markets. Considering the remoteness of wind farms equipped with P2G systems and the isolation of different energy markets, the scheduling process may suffer from inefficient coordination and unstable information. An automated scheduling approach is thus proposed. Firstly, an automated scheduling framework enabled by smart contract is established for reliable coordination between wind farms and multiple energy markets. Considering the limited logic complexity and insufficient calculation of smart contracts, an off-chain procedure as a workaround is proposed to avoid complex on-chain solutions. Next, a non-linear model of the P2G system is developed to enhance the accuracy of scheduling results. The scheduling strategy takes into account not only the revenues from multiple energy trades, but also the penalties for violating contract items in smart contracts. Then, the implementation of smart contracts under a blockchain environment is presented with multiple participants, including voting in an agreed scheduling result as the plan. Finally, the case study is conducted in a typical two-stage scheduling process—i.e., day-ahead and real-time scheduling—and the results verify the efficiency of the proposed approach.

Real-Time Scheduling Procedures Based on Autonomous Distributed Manufacturing System (ADiMS) Concept

2014 ◽  
Vol 660 ◽  
pp. 1010-1014
Author(s):  
Yuwana M. Yatna ◽  
Sri Raharno ◽  
Rifki Ruriardi
Keyword(s):  
Real Time ◽  
Production Scheduling ◽  
Manufacturing Systems ◽  
Manufacturing System ◽  
Scheduling Problems ◽  
Production Schedule ◽  
Distributed Manufacturing ◽  
Real Time Scheduling ◽  
Time Scheduling

This paper deals with the implementation of Autonomous Distributed Manufacturing System (ADiMS) concept in real-time scheduling in order to solve scheduling problems. Basically production scheduling is an important thing and has significant role in manufacturing system. Generally unpredictable conditions such as machine breakdown, absenteeism, or material shortages, in manufacturing system are a problem. These conditions will make the production schedule could not be implemented as planned. However, these conditions are difficult to be avoided and almost always occur in manufacturing systems. A real-time scheduling based on ADiMS concept that provide flexibility, adaptability, and capable could be use to face this problem. In this paper, the problem is limited to real-time scheduling procedures. The result of the case study is every process has been scheduled real-time manually in certain order by the real-time scheduling procedures based on ADiMS. This is showed that ADiMS concept could be implemented in a real-time scheduling and provides flexibility, adaptability, and capable to solve the scheduling problems.

scholarly journals Real Time Scheduling of Nonidentical Multiple Batch Processors with Machine Eligibility Restriction

2021 ◽  
Vol 6 (6) ◽  
pp. 1460-1486
Author(s):  
M. Vimala Rani ◽  
M. Mathirajan
Keyword(s):  
Real Time ◽  
Heuristic Algorithm ◽  
Real Life ◽  
Dispatching Rules ◽  
Total Weighted Tardiness ◽  
Release Time ◽  
Due Date ◽  
Real Time Scheduling ◽  
Machine Eligibility ◽  
Time Scheduling

This study addresses a new problem on scheduling of nonidentical multiple diffusion furnaces (NMDF) with machine eligibility restriction (MER) along with important real-life problem characteristics such as multiple and incompatible job-families, different release time, different due-date, non-agreeable release time & due-date, and occurrences of randomly and dynamically generated real time events (jobs and/or resources related) to minimize total weighted tardiness. Due to the computational difficulty in obtaining an optimal solution for large real-life sized scheduling of NMDF, an alternate solution procedure: heuristic algorithm based on due-date based dispatching rule, called due-date based heuristic algorithm (DDHA) is constructed in this study. Though there has been extensive scheduling research relating to the use of existing dispatching rules in semiconductor manufacturing along with/without new dispatching rules, there is no comparative analysis of all due-date based dispatching rules for real time scheduling (RTS) of NMDF-MER. Hence, this study proposes 20 variants of DDHA, considering various due-date based dispatching rules, for RTS-NMDF-MER and compares their performance. A suitable experimental design is developed and randomly generated 270 instances to represent the research problem considered in this study. From the empirical and statistical analysis carried out in this study, the better performing DDHA(s), for RTS-NMDF-MER, are identified.

Sign in / Sign up

Export Citation Format

Share Document