![WeeklySchedule](https://upload.wikimedia.org/wikipedia/commons/e/e8/WeeklySchedule.png)
A schedule or a timetable, as a basic
time-management
Time management is the process of planning and exercising conscious control of time spent on specific activities, especially to increase effectiveness, efficiency, and productivity. It involves of various demands upon a person relating to work, s ...
tool, consists of a list of times at which possible
tasks, events, or actions are intended to take place, or of a
sequence of events
Time is the continued sequence of existence and events that occurs in an apparently irreversible succession from the past, through the present, into the future. It is a component quantity of various measurements used to sequence events, to ...
in the chronological order in which such things are intended to take place. The process of creating a schedule — deciding how to order these tasks and how to commit resources between the variety of possible tasks — is called scheduling,
[Ofer Zwikael, John Smyrk, ''Project Management for the Creation of Organisational Value'' (2011), p. 196: "The process is called scheduling, the output from which is a timetable of some form".
] and a person responsible for making a particular schedule may be called a scheduler. Making and following schedules is an ancient human activity.
Some scenarios associate this kind of planning with learning
life skills
Life skills are abilities for adaptive and positive behavior that enable humans to deal effectively with the demands and challenges of life. This concept is also termed as psychosocial competency. The subject varies greatly depending on social norm ...
.
Schedules are necessary, or at least useful, in situations where individuals need to know what time they must be at a specific location to receive a specific service, and where people need to accomplish a set of goals within a set time period.
Schedules can usefully span both short periods, such as a daily or weekly schedule, and long-term planning with respect to periods of several months or years. They are often made using a
calendar
A calendar is a system of organizing days. This is done by giving names to periods of time, typically days, weeks, months and years. A date is the designation of a single and specific day within such a system. A calendar is also a physi ...
, where the person making the schedule can note the dates and times at which various events are planned to occur. Schedules that do not set forth specific times for events to occur may instead list
algorithm
In mathematics and computer science, an algorithm () is a finite sequence of rigorous instructions, typically used to solve a class of specific Computational problem, problems or to perform a computation. Algorithms are used as specificat ...
ically an expected order in which events either can or must take place.
In some situations, schedules can be uncertain, such as where the conduct of daily life relies on environmental factors outside human control. People who are
vacationing
A vacation (American English) or holiday (British English) is either a leave of absence from a regular job or an instance of leisure travel away from home. People often take a vacation during specific holiday observances or for specific festiv ...
or otherwise seeking to reduce
stress
Stress may refer to:
Science and medicine
* Stress (biology), an organism's response to a stressor such as an environmental condition
* Stress (linguistics), relative emphasis or prominence given to a syllable in a word, or to a word in a phrase ...
and achieve
relaxation may intentionally avoid having a schedule for a certain period of time.
Kinds of schedules
Publicly available schedules
Certain kinds of schedules reflect information that is generally made available to the public, so that members of the public can plan certain activities around them. These may include things like:
* Hours of operation of businesses, tourist attractions, and government offices, which allow consumers of these services to know when they can obtain them.
* Transportation schedules, such as
airline timetable
Airline timetables are printed pamphlets or folders that many airlines have traditionally used to inform passengers of several different things, such as schedules, fleet, security, in-flight entertainment, food menus, baggage weight restrictions, a ...
s,
train schedule
A public transport timetable (also timetable and North American English schedule) is a document setting out information on public transport service times, to assist passengers with planning a trip. Typically, the timetable will list the times w ...
s,
bus schedule
A public transport timetable (also timetable and North American English schedule) is a document setting out information on public transport service times, to assist passengers with planning a trip. Typically, the timetable will list the times w ...
s, and various
public transport timetable
A public transport timetable (also timetable and North American English schedule) is a document setting out information on public transport service times, to assist passengers with planning a trip. Typically, the timetable will list the times w ...
s are published to allow commuters to plan their travels. From the perspective of the organization responsible for making transportation available, schedules must provide for the possibility of
schedule delay {{no footnotes, date=May 2014
Schedule delay is a term in transport modelling which refers to a difference between a desired time of arrival or departure and the actual time. Despite the use of "delay", it can refer to a difference in either the ea ...
, a term in transport modeling which refers to a difference between a desired time of arrival or departure and the actual time. Despite the use of "delay", it can refer to a difference in either the early or late direction.
* In
broadcast programming
Broadcast programming is the practice of organizing or ordering (scheduling) of broadcast media shows, typically radio and television, in a daily, weekly, monthly, quarterly or season-long schedule.
Modern broadcasters use broadcast automatio ...
, the minute planning of the content of a radio or television broadcast channel, the result of that activity is the generation of a list of shows to be broadcast at regular times or at specific times, which is then distributed to the public so that the potential audience for the show will know when it will be available to them.
*
Concert
A concert is a live music performance in front of an audience. The performance may be by a single musician, sometimes then called a recital, or by a musical ensemble, such as an orchestra, choir, or band. Concerts are held in a wide variety a ...
s and
sporting events
Sport pertains to any form of Competition, competitive physical activity or game that aims to use, maintain, or improve physical ability and Skill, skills while providing enjoyment to participants and, in some cases, entertainment to specta ...
are typically scheduled so that fans can plan to buy tickets and attend the events.
Internal schedules
An internal schedule is a schedule that is only of importance to the people who must directly abide by it. It has been noted that "groups often begin with a schedule imposed from the outside, but effective groups also develop an internal schedule that sets goals for the completion of micro-tasks". Unlike schedules for public events or publicly available amenities, there is no need to go to the time and effort of publicizing the internal schedule. To the contrary, an internal schedule may be kept confidential as a matter of security or propriety.
An example of an internal schedule is a
workplace schedule, which lists the hours that specific employees are expected to be in a workplace, ensure sufficient staffing at all times while in some instances avoiding overstaffing. A work schedule for a business that is open to the public must correspond to the hours of operation of the business, so that employees are available at times when customers are able to use the services of the business. One common method of scheduling employees to ensure the availability of appropriate resources is a
Gantt chart
A Gantt chart is a type of bar chart that illustrates a project schedule, named after its popularizer, Henry Gantt (1861–1919), who designed such a chart around the years 1910–1915. Modern Gantt charts also show the dependency relationship ...
. Another example of an internal schedule is the class schedule of an individual student, indicating what days and times their classes will be held.
Project management scheduling
A schedule may also involve the completion of a project with which the public has no interaction public prior to its completion. In
project management
Project management is the process of leading the work of a team to achieve all project goals within the given constraints. This information is usually described in project documentation, created at the beginning of the development process. Th ...
, a formal schedule will often be created as an initial step in carrying out a specific project, such as the construction of a building, development of a product, or launch of a program. Establishing a
project management schedule involves listing milestones, activities, and deliverables with intended start and finish dates, of which the scheduling of employees may be an element. A
production process schedule is used for the planning of the production or the operation, while a
resource schedule aids in the logistical planning for sharing resources among several entities.
In such cases, a schedule "is obtained by estimating the duration of each task and noting any dependencies amongst those tasks".
Dependencies, in turn, are tasks that must be completed in order to make other tasks possible, such as renting a truck before loading materials on the truck (since nothing can be loaded until the truck is available for things to be loaded on).
Scheduling of projects, therefore, requires the identification of all of the tasks necessary to complete the project, and the earliest time at which each task can be completed.
In creating a schedule, a certain amount of time is usually set aside as a contingency against unforeseen days. This time is called scheduling variance, or
float
Float may refer to:
Arts and entertainment Music Albums
* ''Float'' (Aesop Rock album), 2000
* ''Float'' (Flogging Molly album), 2008
* ''Float'' (Styles P album), 2013
Songs
* "Float" (Tim and the Glory Boys song), 2022
* "Float", by Bush ...
,
and is a core concept for the
critical path method.
In computing
Scheduling is important as an internal process in
computer science
Computer science is the study of computation, automation, and information. Computer science spans theoretical disciplines (such as algorithms, theory of computation, information theory, and automation) to Applied science, practical discipli ...
, wherein a
schedule
A schedule or a timetable, as a basic time-management tool, consists of a list of times at which possible tasks, events, or actions are intended to take place, or of a sequence of events in the chronological order in which such things are i ...
is a list of actions from a set of transactions in databases, and
scheduling
A schedule or a timetable, as a basic time-management tool, consists of a list of times at which possible task (project management), tasks, events, or actions are intended to take place, or of a sequence of events in the chronological order ...
is the way various processes are assigned in
computer multitasking
In computing, multitasking is the concurrent execution of multiple tasks (also known as processes) over a certain period of time. New tasks can interrupt already started ones before they finish, instead of waiting for them to end. As a result ...
and multiprocessing operating system design. This kind of scheduling is incorporated into the computer program, and the user may be completely unaware of what tasks are being carried out and when. Scheduling operations and issues in computing may include:
* The operation of a
network scheduler
A network scheduler, also called packet scheduler, queueing discipline (qdisc) or queueing algorithm, is an arbiter on a node in a packet switching communication network. It manages the sequence of network packets in the transmit and receive q ...
or packet scheduler, an arbiter program that manages the movement of certain pieces of information in the computer.
*
Open-shop scheduling Open-shop scheduling or open-shop scheduling problem (OSSP) is an optimization problem in computer science and Operations Research, operations research. It is a variant of optimal job scheduling. In a general job-scheduling problem, we are given ''n ...
,
Job Shop Scheduling Job-shop scheduling, the job-shop problem (JSP) or job-shop scheduling problem (JSSP) is an optimization problem in computer science and operations research. It is a variant of optimal job scheduling. In a general job scheduling problem, we are give ...
,
Flow Shop Scheduling Problem, optimization problems in computer science.
*
I/O scheduling
Input/output (I/O) scheduling is the method that computer operating systems use to decide in which order I/O operations will be submitted to storage volumes. I/O scheduling is sometimes called disk scheduling.
Purpose
I/O scheduling usually ...
, the order in which I/O requests are submitted to a block device in operating systems.
*
Job scheduler
A job scheduler is a computer application for controlling unattended background program execution of jobs. This is commonly called batch scheduling, as execution of non-interactive jobs is often called batch processing, though traditional ''job'' ...
, an enterprise software application in charge of unattended background executions.
In wireless communications
Wireless network
A wireless network is a computer network that uses wireless data connections between network nodes.
Wireless networking is a method by which homes, telecommunications networks and business installations avoid the costly process of introducing c ...
s should have a flexible service architecture to integrate different types of services on a single
air-interface because
terminal
Terminal may refer to:
Computing Hardware
* Terminal (electronics), a device for joining electrical circuits together
* Terminal (telecommunication), a device communicating over a line
* Computer terminal, a set of primary input and output devic ...
s have different service requirements. On top of the flexible service architecture, effective
quality of service
Quality of service (QoS) is the description or measurement of the overall performance of a service, such as a telephony or computer network, or a cloud computing service, particularly the performance seen by the users of the network. To quantitat ...
(QoS) management schemes are also needed. Therefore, wireless resources need to be shared among all terminals carefully and it is desirable to schedule the usage of wireless resources as efficiently as possible, while maximizing the overall network performance.
In operations research
The scheduling of resources, usually subject to constraints, is the subject of several problems that are in the area of research known as
operations research
Operations research ( en-GB, operational research) (U.S. Air Force Specialty Code: Operations Analysis), often shortened to the initialism OR, is a discipline that deals with the development and application of analytical methods to improve deci ...
, usually in terms of finding an optimal solution or method for solving.
For example, the
nurse scheduling problem
The nurse scheduling problem (NSP), also called the nurse rostering problem (NRP), is the operations research problem of finding an optimal way to assign nurses to shifts, typically with a set of hard constraints which all valid solutions must foll ...
is concerned with scheduling a number of employees with typical constraints such as rotation of shifts, limits on overtime, etc. The
travelling salesman problem
The travelling salesman problem (also called the travelling salesperson problem or TSP) asks the following question: "Given a list of cities and the distances between each pair of cities, what is the shortest possible route that visits each cit ...
is concerned with scheduling a series of journeys to minimize time or distance. Some of these problems may be solved efficiently with
linear programming
Linear programming (LP), also called linear optimization, is a method to achieve the best outcome (such as maximum profit or lowest cost) in a mathematical model whose requirements are represented by linear function#As a polynomial function, li ...
, but many scheduling problems require integer variables. Although efficient algorithms exist to give integer solutions in some situations (see
network flow models), most problems that require integer solutions cannot yet be solved efficiently.
In transportation planning
Scheduling is useful in
transportation planning
Transportation planning is the process of defining future policies, goals, investments, and spatial planning designs to prepare for future needs to move people and goods to destinations. As practiced today, it is a collaborative process that i ...
. The important components of transportation improvement proposals include (a) comprehensive evaluations of the scope of work to be completed, (b) reasonably accurate cost estimates for finishing the task, and (c) a feasible project schedule. If any of these factors are not accurately defined, then there is a strong possibility of unexpected difficulties. Poor scoping and/or scheduling may result in serious budget problems, delays and cancellations of transportation improvements, and sometimes even a
domino effect
A domino effect or chain reaction is the cumulative effect generated when a particular event triggers a chain of similar events. This term is best known as a mechanical effect and is used as an analogy to a falling row of dominoes. It typically ...
that can negatively impact the entire area's transportation planning.
In education
In an educational institution, a timetable must be established that refers students and teachers to classrooms each hour. The challenge of constructing this schedule for larger institutions was addressed by
Gunther Schmidt
Gunther Schmidt (born 1939, Rüdersdorf) is a German mathematician who works also in informatics.
Life
Schmidt began studying Mathematics in 1957 at Göttingen University. His academic teachers were in particular Kurt Reidemeister, Wilhelm K ...
and Thomas Ströhlein in 1976.
Gunther Schmidt
Gunther Schmidt (born 1939, Rüdersdorf) is a German mathematician who works also in informatics.
Life
Schmidt began studying Mathematics in 1957 at Göttingen University. His academic teachers were in particular Kurt Reidemeister, Wilhelm K ...
and Thomas Ströhlein (1976) "A Boolean matrix iteration in timetable construction", Linear Algebra and Its Applications
''Linear Algebra and its Applications'' is a biweekly peer-reviewed mathematics journal published by Elsevier and covering matrix theory and finite-dimensional linear algebra.
History
The journal was established in January 1968 with A.J. Hoffma ...
15(1):27–51 They formalized the timetable construction problem, and indicated an iterative process using
logical matrices and
hypergraph
In mathematics, a hypergraph is a generalization of a graph in which an edge can join any number of vertices. In contrast, in an ordinary graph, an edge connects exactly two vertices.
Formally, an undirected hypergraph H is a pair H = (X,E) wh ...
s to obtain a solution.
See also
*
Automated planning and scheduling
Automation describes a wide range of technologies that reduce human intervention in processes, namely by predetermining decision criteria, subprocess relationships, and related actions, as well as embodying those predeterminations in machines ...
*
Calendaring software
A digital calendar is a collaborative or personal time management software with a calendar that can be used to keep track of planned events. The calendar can also contain an appointment book, address book or contact list. Common features of d ...
*
Employee scheduling software Employee scheduling software automates the process of creating and maintaining a schedule. Automating the scheduling of employees increases productivity and allows organizations with hourly workforces to re-allocate resources to non-scheduling acti ...
*
Notation for theoretic scheduling problems Optimal job scheduling is a class of optimization problems related to scheduling. The inputs to such problems are a list of ''jobs'' (also called ''processes'' or ''tasks'') and a list of ''machines'' (also called ''processors'' or ''workers''). The ...
*
Timeblocking Timeblocking or ''time blocking'' (also known as ''time chunking'') is a productivity technique for personal time management where a period of time—typically a day or week—is divided into smaller segments or blocks for specific tasks or to-dos. ...
References
{{Reflist
Time management
Scheduling (computing)