Percent Idle Time

The Percent Idle Time calculator compute the percent of idle time as a function of the cycle time, number of stations, and the idle time.

INSTRUCTIONS: Choose the preferred units and enter the following:

• (IDT)  Idle time per cycle
• (N) Number of stations
• (CT) Cycle Time is max time allocated at a station to complete the task for the unit processed.

Percent Idle (P): The calculator returns the percent idle.  However this can be automatically converted to a real number via the pull-down menu.

The Math / Science

Reducing idle time in the workplace is always a goal of management. In order to find ways to increase productivity while reducing employee inactivity, the actual time spent idle must be quantified. Idle time in most professional settings is defined as that which was previously scheduled for an activity, but, for some unforeseen or known reason, was lost in an unproductive manner, and thus could not be reallocated to another project or revenue-generating activity.

The formula for percent idle time is :

        P  = IDT / (N•CT)

where:

• P is the percent idle time
• CT is the Cycle time, the Time between Units
• N is the number of stations
• IDT is the idle time per cycle

Application

Line Balancing
 Line balancing is the process of assigning tasks to workstations, so that workstations have approximately equal time requirements. We use line balancing to
 - minimize idle time
 - balance bottlenecks
 What is a bottleneck?

Literally what is line balancing? Imagine pouring out a bottle of coke. What does the neck of the bottle do to the flow of the coke out of the bottle? Does the neck of the bottle have the same capacity as the base?
 1.In product layouts, when we want to improve productivity, we need to find and improve critical operations, known as bottlenecks. Productivity improvements to any non-bottleneck operation will NOT improve productivity of the system.

Time Management Calculators

• Amdahl's Law: Compute the overall speedup factor based on an improvement of a portion of the process. 
• Units over Time:  Enter the amount of time (P) to produce or consume a number of units (N), then enter the time (T) of production or consumption and this will tell you the number of units produced in that period (X).
• Time for Units:  Enter the number of units (N) produced or consumed in a period of time (P). Then enter the number you wish to achieve, produce or consume, (X), and this will tell you the period of time (T) needed to process the number of units.
• Length over Time:  Enter the unit length (uL) achieved in a given duration unit of time (dU), and then specify the Total Period (P), the calculator will compute the Total Length processed over time.
• Time for Length:  Enter the unit length (uL) achieved in a given duration of unit time (dU), and then specify the Total Length (TL) you wish to achieve.  The calculator computes the Total Period (P) required required to process the length.
• Area over Time: Enter the  unit area (uA) processed in a given duration unit of time (dU), and then specify the Total Period (P), the calculator with compute the Total Area (TA) processed in the Total Period.
• Time for Area:  Enter the unit area (uA) processed in a given duration unit of time (dU), and then specify the Total Area (TA) you wish to process.  The calculator computes the Total Period (P) required to process the Total Area.
• Volume over Time: Enter the  unit volume (uV) processed in a given duration unit of time (dU), and then specify the Total Period (P), the calculator with compute the Total Volume (TV) processed in the Total Period.
• Time for Volume:  Enter the unit volume (uV) processed in a given duration unit of time (dU), and then specify the Total Volume (TV) you wish to process.  The calculator computes the total time period (P) required to process the Volume.