Multitasking (redirect from Multi-tasking)

Computer multitasking - the apparent simultaneous performance of two or more

Multitasking (redirect from Multi-tasking)

Computer multitasking - the apparent simultaneous performance of two or more

Multithreading

As multitasking greatly improved the throughput of computers, programmers started to implement applications as sets of cooperating processes (e.g. one process gathering input data, one process processing input data, one process writing out results on disk). This, however, required some tools to allow processes to efficiently exchange data.

Time management

Time management refers to a range of skills, tools, and techniques used to manage time when accomplishing specific tasks, projects and goals. This set encompass a wide scope of activities, and these include planning, allocating, setting goals, delegation, analysis of time spent, monitoring, organizing, scheduling, and prioritizing. Initially time management referred to just business or work activities, but eventually the term broadened to include personal activities also. A time management system is a designed combination of processes, tools and techniques.

How We Use Time

When we spend time, there is no improvement in efficiency, productivity, or effectiveness. The time is gone without a return. We save time when we perform tasks in less time or with less effort than previously. We use shortcuts and processes that streamline activities. We invest time when we take time now to save time later.

Computer multitasking (redirect from Multi-programming)

In computing, multitasking is a method by which multiple tasks, also known as ... number of I/O processors, a kind of asymmetric multi-processing .

Programming in a multitasking environment

Processes that are entirely independent are not much trouble to program. Most of the complexity in multitasking systems comes from the need to share computer resources between tasks and to synchronize the operation of co-operating tasks. Various concurrent computing techniques are used to avoid potential problems caused by multiple tasks attempting to access the same resource.

Memory protection
When multiple programs are present in memory, an ill-behaved program may (inadvertently or deliberately) overwrite memory belonging to another program, or even to the operating system itself.

Memory swapping
Use of a swap file or swap partition is a way for the operating system to provide more memory than is physically available by keeping portions of the primary memory in secondary storage. While multitasking and memory swapping are two completely unrelated techniques, they are very often used together, as swapping memory allows more tasks to be loaded at the same time.

Real time

Another reason for multitasking was in the design of real-time computing systems, where there are a number of possibly unrelated external activities needed to be controlled by a single processor system. In such systems a hierarchical interrupt system was coupled with process prioritization to ensure that key activities were given a greater share of available process time.

Human multitasking

Human multi-tasking or multitasking is the performance by an individual of appearing to handle more than one task at the same time.

Human reliability

Human reliability is related to the field of human factors engineering, and refers to the reliability of humans in fields such as manufacturing, transportation, the military, or medicine. Human performance can be affected by many factors such as age, state of mind, physical health, attitude, emotions, propensity for certain common mistakes, errors and cognitive biases, etc.

PRA-Based Techniques
One method for analyzing human reliability is a straightforward extension of probabilistic risk assessment (PRA): in the same way that equipment can fail in a plant, so can a human operator commit errors. In both cases, an analysis (functional decomposition for equipment and task analysis for humans) would articulate a level of detail for which failure or error probabilities can be assigned.

Cognitive Control Based Techniques

Erik Hollnagel has developed this line of thought in his work on the Contextual Control Model (COCOM) (Hollnagel, 1993) and the Cognitive Reliability and Error Analysis Method (CREAM) (Hollnagel, 1998). COCOM models human performance as a set of control modes—strategic (based on long-term planning), tactical (based on procedures), opportunistic (based on present context), and scrambled (random) -- and proposes a model of how transitions between these control modes occur

Related Techniques

Related techniques in safety engineering and reliability engineering include Failure mode and effects analysis, Hazop, Fault tree, and SAPHIRE: Systems Analysis Programs for Hands-on Integrated Reliability Evaluations.

Human error

Human error has been cited as a cause or contributing factor in disasters and accidents in industries as diverse as nuclear power (e.g., Three Mile Island accident), aviation (see pilot error), space exploration (e.g., Space Shuttle Challenger Disaster), and medicine (see medical error). It is also important to stress that "human error" mechanisms are the same as "human performance" mechanisms; performance later categorized as 'error' is done so in hindsight (Reason, 1991; Woods, 1990): therefore actions later termed "human error" are actually part of the ordinary spectrum of human behaviour.

Categories of Human Error

*There are many ways to categorize human error (see Jones, 1999; Wallace and Ross, 2006).
*exogenous versus endogenous (i.e., originating outside versus inside the individual) (Senders and Moray, 1991)
*situation assessment versus response planning (e.g., Roth et al., 1994) and related distinctions in
- errors in problem detection (also see signal detection theory)
- errors in problem diagnosis (also see problem solving)
- errors in action planning and execution (Sage, 1992) (for example: slips or errors of execution versus mistakes or errors of intention; see Norman, 1988; Reason, 1991)
*By level of analysis; for example, perceptual (e.g., optical illusions) versus cognitive versus communication versus organizational.

The Human Factors Analysis and Classification System (HFACS)

The Human Factors Analysis and Classification System (HFACS) was developed initially as a framework to understand "human error" as a cause of aviation accidents (Shappell and Wiegmann, 2000; Wiegmann and Shappell, 2003). It is based on James Reason's Swiss cheese model of human error in complex systems.

Multiprogramming

Multiprogramming should be differentiated from multi-tasking since not all multiprogramming entails—or has the capability for-- "true"

Media multitasking

Media multitasking involves using TV, the Web, radio, telephone, print, or any other media in conjunction with another. Also referred to as "simultaneous media use," this behavior has emerged as increasingly common, especicially among younger media users,and has gained significant attention in media usage measurement, especially as a new opportunity for cross-media advertising.