A view of concurrent process synchronisation

In order to make a rational planning of CAPP-PPC process, the differences of product serial and concurrent CAPP-PPC process were studyed in this paper. Based on Witness, Three kinds of product serial and concurrent CAPP-PPC process simulation model were established for products with different complicated degrees. Simulation results show the time of concurrent process is much shorter than serial process, for complex products, especially obvious.

Download Full-text

A New Deadlock Avoidance Policy Based on Petri Nets in Distributed System

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.743.575 ◽

2015 ◽

Vol 743 ◽

pp. 575-580

Author(s):

B.W. Liu

Keyword(s):

Petri Nets ◽

Distributed System ◽

Traditional Method ◽

Deadlock Avoidance ◽

Reachability Graph ◽

Concurrent Process

Distributed system has the characteristic of high concurrency, which often leads to deadlock due to the execution of concurrent process. By applying Petri nets model can effectively solve this problem. In this paper, based on Petri nets model, we propose a new efficient deadlock avoidance policy for distributed system by using the Petri reachability graph. At last we analysis the different performance between this algorithm and the traditional method by using Matlab tool.

Download Full-text

An Exploratory Study on Optimal Iterative Design Schedules with the Consideration of Design Quality and Resource Constraints

Sustainability ◽

10.3390/su13084584 ◽

2021 ◽

Vol 13 (8) ◽

pp. 4584

Author(s):

Sou-Sen Leu ◽

Theresia Daisy Nattali Suparman ◽

Cathy Chang-Wei Hung

Keyword(s):

Design Process ◽

Completion Time ◽

Resource Constraints ◽

Design Quality ◽

Concurrent Process ◽

Dependency Structure ◽

Iterative Design ◽

Scheduling Model ◽

Design Schedule ◽

Dependency Structure Matrix

The classical dependency structure matrix (DSM) can effectively deal with iterative schedules that are highly coupled and interdependent, such as the design process and the concurrent process. Classical DSM generally follows the assumption that the least iteration occurs to achieve the shortest completion time. Nevertheless, the assumption may not hold because tasks ought to be re-visited several times if the design qualities do not meet the requirements. This research proposed a novel iterative scheduling model that combines the classical DSM concept with quality equations. The quality equations were used to determine the number of tasks that ought to be re-visited for fulfilling quality requirements during the iterative design process. Moreover, resources for concurrent activities are generally limited in the real world. Resource allocation should be incorporated in scheduling to avoid the waste and shortage of resources on a design project. This research proposed a new iterative scheduling model based on the classical DSM to optimize the iterative activities’ structure in terms of minimizing completion time with the consideration of design quality under resource constraints. A practical design schedule was introduced to demonstrate the applicability of the proposed DSM algorithm.

Download Full-text