A printed record that shows the pattern of acceleration and deceleration of an anatomical reference point in the performance of a task.
Related Terms 
PLAY FOR POSITION
The prepositioning of an object by a worker for a subsequent operation in the performance of a task.

PLASTICORDER
Laboratory device used to predict the performance of a plastic material by measurement of temperature, viscosity, and shearrate relationships. Also known as plastigraph.

PLANE OF WORK
The plane in which most of a worker's motions occur in the performance of a task.

PERFORMANCE EFFORT RATING
A technique in work measurement used to determine the leveling factor to be applied to an operator or a group of operators by short, randomly spaced observations of the performance index.

PERFORMANCE CHART
Graphical representations showing the abilities of rotating equipment at various operating conditions; for example, the performance curve for a compressor would include rotor speed for various intake and outlet pressures versus gas flow rate adjusted for temperature, density, viscosity, head, and other factors.

OPTIMAL CONTROL THEORY
An extension of the calculus of variations for dynamic systems with one independent variable, usually time, in which control (input) variables are determined to maximize (or minimize) some measure of the performance (output) of a system while satisfying specified constraints.

MERIT
A performance rating that governs the choice of a device for a particular application; it must be qualified to indicate type of rating, as in gainbandwidth merit or signaltonoise merit.

MEANSQUAREERROR CRITERION
Evaluation of the performance of a control system by calculating the square root of the average over time of the square of the difference between the actual output and the output that is desired.

MACHINE CAPABILITY
A qualitative or quantitative statement of the performance potential of a specific item of power equipment.

LINEAR REGULATOR PROBLEM
A type of optimal control problem in which the system to be controlled is described by linear differential equations and the performance index to be minimized is the integral of a quadratic function of the system state and control functions. Also known as optimal regulator problem; regulator problem.
