Estimate Analysis
A service for Manufacturing Management from Assured Systems
Estimate Analysis involves looking at time estimates from several angles. We compare
estimates with actuals looking from a new point of view. We see if there is bias or trends in the
estimates rather than in the actuals.
We also look at the estimates themselves to see if there is inconsistency between similar
estimates, eg different parts made by the same process. This can happen over a period of time
as changes happen in the plant, but the impact on various parts is neglected.
This work is done statistically, using existing data extracted from your business system.
Here is an example.
Australia is the home of short runs.
This means that for Australian producers setup time is a big part of the cost.
Most companies allow for setup time in the time estimate, but how many actually verify
that the setup time is real? You could try getting the shop floor people to report set time
separately, or, if you know how, actual setup time can be extracted from existing data.
Assume we have records of time taken on jobs.
Different runs of the same part over a few months. Only the durations have been reported
| Date of Run |
Quantity
Produced |
Reported
Time Taken |
| 25/1 |
5000 |
12 hrs |
| 24/2 |
10000 |
22 hrs |
We assume that the job time is the total of set up time and production time.
Assume set up time is fixed regardless of quantity.
Production time depends on the run quantity and the time per piece.
| Date of Run |
Quantity
Produced |
Reported Time
Taken |
Set Time |
Production Time |
| 25/1 |
5000 |
12 hrs |
unknown S |
5000 x unknown P |
| 24/2 |
10000 |
22 hrs |
unknown S |
10000 x unknown P |
The solver tells us that setup time S is 2 hrs, and piece time P is 0.002 hr or 500 parts/hr.
As the Managing Director said, "you are solving 2 simultaneous equations with 2
unknowns. That is year 9 math. What's new?" The difficulty is to take a large
quantity of data, locate what is significant and what is not, do it reliably and present
the results in a useful format
Assured Systems has the expertise and tools to help you with Estimate Analysis. We can
work with your people in an advisory role, or actually perform the study for you, or you can
send a delegate to one of our seminars on Estimate Analysis.
for more information
Contact: Assured Systems Tel: 03 9555 7222
email: info@assuredsystems.com.au
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