This document explains how the Global KPIs Solution calculates Surface Mount Technology (SMT) manufacturing Key Performance Indicators (KPIs). It provides a "bottom-up explanation" starting from a single Pick and Place (PnP) machine and working up through Lines, Areas, Sites, Regions, and Globally. Once you understand how the KPIs for a single Pick and Place machine are calculated, all the other KPIs flow from that. For a "top-down explanation," see How SMT Manufacturers Analyze Time and Productivity.
Pick and Place (PnP) Machine KPIs
By default, SMT manufacturing assembly line performance is measured in placements performed by Pick and Place (PnP) machines. (Other units such as Boards or Panels are also possible.) So we start by evaluating the performance of the individual PnP.
The (Derated) Target for a PnP
Each PnP model/head combination has a Theoretical Target in Chips Per Hour (CPH) defined by the machine's vendor. For example, the vendor "BusyBot" might say that their ChipBot 1000 model with a 200X head has a Theoretical Target of 200,000 CPH.
Manufacturers may use the vendor's Theoretical Target to measure the PnP's performance. More commonly, they define their own "Derated Target" (hereafter, just the "Target") based on the results of their own internal performance testing, whether the PnP is being used on a New Product Introduction (NPI) or Production line, and/or what kind of product the PnP is assembling.
So in our example, the manufacturer might assign that BusyBot ChipBot 1000 with the 200X head a (derated) Target of 150,000 CPH when used on a Mass Production (MP) line.
Throughput for a machine is simply the count of how many chips it has successfully placed during a period of time (such as a day or week).
Planned Production Time
The manufacturer uses ArchFX Cloud to specify which hours of each day are a site's Planned Production Time. For example, at a site with two shifts, Planned Production Time might be 5 a.m. to 9 p.m. local time.
A machine's Availability is the percentage of Planned Production Time during which production took place. Global KPIs Solution measures Availability in 15-minute intervals. If any production took place during the 15-minute interval, the machine was Available.
Availability % = (Actual Production Time) / (Planned Production Time) * 100
So if there were 16 hours of Planned Production Time and the machine placed chips during 12 hours, Availability was 75%.
Speed measures how quickly the PnP was placing chips when it was active.
Speed in CPH = (Throughput during period, in placements) / (hours of Availability during period)
If the machine placed 1,200,000 chips in 12 hours of Availability:
Speed = 1,200,000 chips / 12 hours = 100,000 CPH
Performance measures the percentage of the Target the machine achieved when it was producing. In other words: did it perform as expected when it was working?
Performance % = (Throughput during period, in placements) / (Target * Hours of Availability) * 100
So if the Target was 150,000 CPH, there were 12 Hours of Availability, and 1,200,000 chips were placed:
Performance = 1,200,000 placements / (150,000 CPH * 12 Hours) * 100 = 67%
Machine Utilization (MU) % measures what portion of a machine's theoretical 24x7x365 production capacity is actually being used in practice.
Machine Utilization % = (Throughput during period) / (Target * total time during period) * 100
So in the example above, there are 24 hours in the day, but the machine which has a Target of 150,000 CPH was only producing for 12 hours and only produced 1,200,000 placements, so:
Machine Utilization % = 1,200,000 placements / ( 150,000 CPH * 24 hours) * 100 = 33%
Throughput for a Line is simply the sum of how many chips were successfully placed during a period of time (such as a day or week) by all PnPs on the Line combined.
Availability for a Line is the portion of Planned Production Time during which chips were placed by any machine on the line.
Line Utilization is the sum of the Throughput of all the machines on the Line during the period of time divided by the total of expected production (Target * time during period) across all the machines on Line, multiplied by 100 to produce a percentage.
Line Utilization % = (total Throughput of Line) / (sum for all Machines of Target * (total time during period)) * 100
In our example, if there were two other BusyBot ChipBot 1000s with 200X heads on the line and one did 800,000 placements and the other did 1,000,000 placements:
Line Utilization % = (3 million placements) / ((150,000 CPH + 150,000 CPH + 150,000 CPH) * 24 hours) * 100 = 27.7 %
Manufacturers often organize Lines into Areas such as floors, halls, or buildings.
- Throughput for an Area is the sum of the Throughput across all the Lines in the Area.
- Availability for an Area is the average of the Availability for all the Lines in the Area.
- Area Utilization is the average of Line Utilization of all the Lines in the Area.
- Throughput for a Site is the sum of the Throughput across all the Lines in the Site.
- Availability for a Site is the average of the Availability for all the Lines in the Site.
- Site Utilization is the average of Line Utilization of all the Lines in the Site.
Regional and Global KPIs
The Global KPIs Solution divides the world into the regions of the Americas, Europe - Middle East - Africa (EMEA), and Asia. There's also a Global "region" that represents the entire world.
- Utilization for a region is the average Line Utilization for all the Lines in the region.