Capacities, Constraints, and Metrics

 

MVP® has traditionally delivered a graphical representation of how tasks are organized throughout the plant.  Whether at a Lumber Picking station, the Saw Shop, or Assembly Shop, MVP users have been able to see the sequence and estimated duration of individual pieces of work.  With recent enhancements, even more accurate scheduling - based on thorough development of work time estimates and available shop floor capacity – is available.

Machine Metrics

Expanded Machine Metrics at the Saw and Assembly workstations in MVP enable precise definition of a workstation’s capabilities.  This deeper understanding for both Setup and Run operations allows MVP to better estimate how long any given piece of work will take.  Once the duration of a task is well defined, it can be more thoroughly scheduled.

Capacities

MVP now allows users to define Standard Daily Capacities and Ad-Hoc Capacities.  Daily Capacities correlate to the normal working day for your employees at work centers.  Ad-Hoc Capacities allow extra capacity to be defined for a given time and can be used to overcome temporary bottlenecks in the plant.  Based on capacities and the manufacturing time estimates garnered from enhanced machine metrics, MVP is able to estimate start and end times for work taking into account when workers are available and when they are not.

The following graphics illustrate the effect of having capacities in MVP: 

Figure 1 illustrates a situation where there are no defined capacities and the different pieces of work are aligned one after the other with no consideration for “real” shop work times.

Figure 1
In Figure 2, MVP capacities have been enabled.  The groups of work now respect the non-working periods – shown as gray bands.  Notice saw batch J09090001-E starts at the end of one work period (the white band), spans the break period, and ends in the next defined work period.
Figure 2

Constraints

 Constraints enable MVP to analyze work based on the ability to get previous work accomplished.  For any given assembly order there are many upstream tasks that must be done in a timely manner to allow the assembly work to be completed “on time.”  Plates and lumber must be picked, splicing might need to occur, and cutting must be done.  If any of those tasks is a constraint, there could be an effect on any or all of the downstream operations.  MVP now gives the console manager the ability to see the effect of the constraints and allows them to be addressed via capacity changes or through the re-assignment of tasks.

The following graphics illustrate a Lumber Staging constraint on Cutting:

Figure 3 shows a non-constrained saw.  The scheduling of the batches is not affected by any upstream operation - they are just sequenced one after the other.

Figure 3

In Figure 4, the same saw has now been constrained by the Lumber Staging operation in MVP.  It is clear that the ability to get lumber picked is influencing the timing of cutting of batches.

Figure 4

Conclusion

With the development of enhanced Machine Metrics, Capacities, and Constraints, MVP provides a tool set that can more closely model and evaluate the status of the shop floor.  These tools will help give visibility to the “ripples” caused by change on the shop floor.  This visibility will allow MVP users to recognize the situation and take corrective action before any manufacturing or delivery due dates are negatively affected. 
 
 

 This page last modified on 10/14/2009