A generic library of problem solving methods for scheduling applications

In this paper we propose a generic library of problem-solving methods for solving scheduling applications. Some attempts have been made in the past at developing a library of scheduling problem-solvers but in some cases these earlier proposals subscribe to a specific application domain of scheduling, which restricted their reusability, while in some other cases they subscribe to the specific problem-solving technique which may be applicable only to a subset of the space of scheduling problems. Finally all the existing scheduling libraries fail to provide an adequate degree of detail and precision. In our approach we subscribe to the Task-Method-Domain-Application knowledge modeling framework which provides a structured organization for the different components of the library. At the task level, we constructed a generic scheduling task ontology to formalize the space of scheduling problems. At the method level, we constructed a generic problem-solving model of scheduling that generalizes from the variety of approaches to scheduling problem-solving, which can be found in the literature. And, then seven knowledge-intensive methods are developed as a specialization of the generic problem-solving model of scheduling. Finally, we validated our library on a number of applications to demonstrate its generic nature and effective support for developing scheduling applications

Scheduling Information System: the Design and Development of an Online Database for Tracking Scheduling Information

This paper describes the design and development of a Web-based scheduling information system. This particular system is intended to allow workers to enter the hours they would like to request to work so that the scheduler can query the database to see who is available to work on which days in order to make the schedule. The workers are able to query the database as well, so that they can see how many other people have requested the days they plan to request for. For data input, the proposed system presents Web-based HTML forms that can be accessed from any Web browser; the system stores the collected information in a MySQL database. PHP scripting language is used to link the HTML forms and the MySQL database; it constructs SQL insert statements to enter data into the database, and constructs queries to extract information from the database

Autonomous Finite Capacity Scheduling using Biological Control Principles

The vast majority of the research efforts in finite capacity scheduling over the past several years has focused on the generation of precise and almost exact measures for the working schedule presupposing complete information and a deterministic environment. During execution, however, production may be the subject of considerable variability, which may lead to frequent schedule interruptions. Production scheduling mechanisms are developed based on centralised control architecture in which all of the knowledge base and databases are modelled at the same location. This control architecture has difficulty in handling complex manufacturing systems that require knowledge and data at different locations. Adopting biological control principles refers to the process where a schedule is developed prior to the start of the processing after considering all the parameters involved at a resource involved and updated accordingly as the process executes. This research reviews the best practices in gene transcription and translation control methods and adopts these principles in the development of an autonomous finite capacity scheduling control logic aimed at reducing excessive use of manual input in planning tasks. With autonomous decision-making functionality, finite capacity scheduling will as much as practicably possible be able to respond autonomously to schedule disruptions by deployment of proactive scheduling procedures that may be used to revise or re-optimize the schedule when unexpected events occur. The novelty of this work is the ability of production resources to autonomously take decisions and the same way decisions are taken by autonomous entities in the process of gene transcription and translation. The idea has been implemented by the integration of simulation and modelling techniques with Taguchi analysis to investigate the contributions of finite capacity scheduling factors, and determination of the ‘what if’ scenarios encountered due to the existence of variability in production processes. The control logic adopts the induction rules as used in gene expression control mechanisms, studied in biological systems. Scheduling factors are identified to that effect and are investigated to find their effects on selected performance measurements for each resource in used. How they are used to deal with variability in the process is one major objective for this research as it is because of the variability that autonomous decision making becomes of interest. Although different scheduling techniques have been applied and are successful in production planning and control, the results obtained from the inclusion of the autonomous finite capacity scheduling control logic has proved that significant improvement can still be achieved

A Generic Library of Problem Solving Methods for Scheduling Applications

In this thesis we propose a generic library of scheduling problem-solving methods. As a first approximation, scheduling can be defined as an assignment of jobs and activities to resources and time ranges in accordance with a number of constraints and requirements. In some cases optimisation criteria may also be included in the problem specification. Although, several attempts have been made in the past at developing the libraries of scheduling problem-solvers, these only provide limited coverage. Many lack generality, as they subscribe to a particular scheduling domain. Others simply implement a particular problem-solving technique, which may be applicable only to a subset of the space of scheduling problems. In addition, most of these libraries fail to provide the required degree of depth and precision, which is needed both to obtain a formal account of scheduling problem solving and to provide effective support for development of scheduling applications by reuse. Our library subscribes to the Task-Method-Domain-Application (TMDA) knowledge modelling framework, which provides a structured organisation for the different components of the library. In line with the organisation proposed by TMDA, we first developed a generic scheduling task ontology, which formalises the space of scheduling problems independently of any particular application domain, or problem solving method. Then we constructed a task-specific, but domain independent model of scheduling problem-solving, which generalises from the variety of approaches to scheduling problem-solving, which can be found in literature. The generic nature of this model was demonstrated by constructing seven methods for scheduling, as alternative specialisation of the model. Finally, we validated our library on a number of applications to demonstrate its generic nature and effective support for the analysis and development of scheduling applications

Інформаційна технологія календарного та оперативного планування в системах з мережевим представленням технологічних процесів

Робота присвячена створенню інформаційної технології (ІТ) календарного та оперативного планування (КОП) в системах з мережевим представленням технологічних процесів на основі високоефективних методів розв’язання задач КОП, формалізації поопераційного мережевого представлення дискретних технологічних процесів, модифікації відомих процедур агрегації та дезагрегації мережевої моделі та узгодженого планування, обґрунтування зведення задачі планування за будь-яким з п’яти базових критеріїв до однієї задачі складання розкладів. Вперше створено цілісний комплекс моделей та методів — чотирьохрівнева модель КОП. Розроблено новий метод розв’язання NP-складної задачі теорії розкладів «Складання розкладу виконання незалежних завдань ідентичними паралельними пристроями, моменти запуску яких менше спільного директивного строку», який дозволяє отримувати точний розв’язок для задач із десятками тисяч змінних при виконанні ознак його оптимальності або наближений розв’язок з оцінкою відхилення від оптимуму при їх невиконанні. Створена інформаційна технологія календарного та оперативного планування в системах з мережевим представленням технологічних процесів. Система використовується на підприємстві ФГ «ЛЕТА» (м. Мукачево)