2014, we use RedZone (rzsoftware.com) OEE Management
product, they build in iPad App to collect PLC data from production machine,
after 1 year running, we found
1.
Data need to manually to import or export with
our MS Navision Database.
2.
Maintenance fee is too high, especial we need to
modify the report.
3.
Operation pages are not customizable per the
process.
So Chris Asby and I use PLC + Touch Screen to build our own “Production
Data Acquisition System” (PDAS).
1.
Industrial waterproof HMI’s with input/output
boards are located on the production floor at predetermine locations. Inputs are hardwired from the production
machinery to these inputs to capture data from machine cycles, case counters,
and any other production data that is needed.
Each HMI also has an external alarm light to notify employees that the
HMI’s need attention (Log downtime or any alarms setup in the system).
2.
HMI’s have a built in webserver and can have
custom HTML websites to show live production data from any web browser. They are also capable of communicating
directly with many PLC’s on the market via many different communication
protocols.
3.
All HMI’s are hardwired to the plant Ethernet
network and all communicate with each other via Modbus TCP. User login id’s restrict access to certain
pages in the system or allow a supervisor to view & change any operation
page from any panel in the system.
4.
Everyday 5:30am, SQL Job agent grab production
order with production Line code from Navision to PDAS server. This information also includes target rates,
target OEE, cases to produce and other values used in the PDAS system to
determine production line rate & performance.
5.
PLC imports this data into each HMI (Typically 2
per production line) as a production schedule for each line.
6.
Production foreman follow up production order
that are list in touch screen to start and end button to record this order
start & end time.
7.
PLC system will track downtime per OEE
sub-category (Performance, Availability, Quality) and enforce logging of the
reason for outage for all downtime per item number that is running in
production.
8.
Reason for outage (RFO) lists are maintained in
CSV format and sync with the panels daily.
This limits the items available to be selected by the operators. RFO tables are unique to the OEE category as
well as the production line. All panels
are capable of sending emails and the operators can send emails requesting an
RFO be added to their list.
9.
Alarm or alert emails can be automatically
generated and sent based on any “tag” information inside the PDAS. For example if a line is down for xx minutes
an email can be sent out to a preselected group of recipients letting them know
that the line is down for xx minutes or the OEE score is below target, etc.
10.
Everyday 5:00 AM, PLC system will export the
previous day’s records to PDAS server (CSV file format) then SQL Job Agent
import into Navision database.
11.
SQL SSAS server update data by schedule then
export to SharePoint Business Intelligence services.
12.
User use browser to view BI in SharePoint PDAS
site.
Our PDAS system detail information is this:
1.
What is OEE anyways?
a.
OEE
is an acronym for Overall Equipment Effectiveness and is made up of 3 elements.
Overall equipment effectiveness quantifies how well a manufacturing unit
performs relative to its designed capacity, during the periods when it is
scheduled to run. OEE allows us to easily measure and communicate equipment
utilization against standards.
b.
OEE
= Performance x Availability x Quality
c.
Performance
= (Parts Produced*Ideal Cycle Time)/Operating Time
d.
Example:
Multivac has produced 3,500 cycles over 8 hours of production with 1 hour of
downtime. Target rate is 10 cycles per minute. (Performance =
(3,500*(10/60=0.1667 minutes per cycle)/(8 hours minus 1 hour of DT=7
hours*60=420 minutes) so… Performance = (3,500*0.1667)/7 which equates to 83%
e.
Note:
The “Operating Time” equals time that the machine is actually running, anytime
the machine output is 0 (Stopped) is accounted for in the availability element
and does not affect the performance element
f.
Availability=
Uptime / Available Time
g.
Example:
The Multivac has just completed an 8 hour run without change overs. Film
changes and waiting for product have caused one hour of accumulated down time
during this shift making the total uptime equal to 7 hours.
h.
Availability
= 7 hours / 8 hours which equates to 87.5%
i.
Quality
= (Units Produced – Defective Units) / Units Produced
j.
Example:
The Multivac cycled 3,500 times during this shift which equated to 14,000 units
(3,500 x 4) of retail product. At the end of the shift the total case count was
2,000 cases which at 6 units per case equates to 12,000 units. This means there
was a 2,000 case loss during the run.
k.
Quality
= (14,000-2,000) / 14,000 which equates to 85.7%
l.
The
examples above would then be combined to calculate the Multivac OEE as follows:
m.
Multivac OEE =
Performance (83%) x Availability (87.5%) x Quality (85.7%) which equates to 62.2%
OEE
2.
Touch
Screen Navigation Tree example (pages are unique to the input type). Pic1
3. Table structure. Pic2
4. Data example. Pic3
5. SSAS measure & Dimension example. Pic 4
