Post on 14-Jan-2016
description
© BMA Inc. 2009. All rights reserved.
Value Stream CapacityUnderstanding Value Stream Decision Making
© BMA Inc. 2009. All rights reserved.
Understanding Value Stream Capacity
• The production quantity that can be achieved at each step in the value stream or production process.
• There are usually one or two production steps (cells, machines, or work centers) that constrain the flow through the value stream or business unit.
• We need to identify the production capacity at each step in the value stream (or production flow) so that we can understand the flow through the entire process.
• Where is the data required for this analysis?– On the Value Stream Maps
© BMA Inc. 2009. All rights reserved.
Analyzing the capacity
Productive capacityValue added activitiesProvides value to the customerComes directly from customer pull
Non-productive capacityNon-value-added activitiesChange-overs, unplanned maintenance, making for stock,
defects/rework, etc. Also meetings, 5S, improvement activity
Available capacityCapacity that is not currently being use for productive or non-
productive activities.
© BMA Inc. 2009. All rights reserved.
OEM Value Stream Map
Supplier Customer
Kanban
Shipping
S&OPDemand ForecastsPurchase Forecasts
Order
Supplier Customer
ShippingShippingAssemblyAssemblyAssemblyAssemblyAssemblyWelding
3,000 per Month
MachineShop
MachineShop
MachineShopMachineShop
MachineShop
MachineShop
MachineShop
Qty = 30,000C/T = 70sBatch = 1500Set Up = 10,800sScrap = 10%Rework = 20%Downtime = 15%Inspection = 10%Insp Time = 120s# cells = 8Crew Size = 4# of people = 34Shifts = 1
Qty = 15,000C/T = 180sBatch = 600Set Up = 1200sScrap = 5%Rework = 10%Downtime = 5%Inspection=100%Insp Time = 30s# cells = 5Crew Size = 1# of people = 10Shifts = 2
Qty = 3,000C/T = 210sBatch = 20Set Up = 600sScrap = 0%Rework = 10%Downtime = 0%Inspection=100%Insp Time = 60s# cells = 2Crew Size = 5# of people = 10Shifts = 1
Qty = 3,000C/T = 120sBatch = 1Set Up = 0sScrap = 0%Rework = 2%Downtime = 0%Inspection=0%Insp Time = 0s# cells = 1Crew Size = 1# of people = 1Shifts = 1
DATA BOXES
© BMA Inc. 2009. All rights reserved.
Cycle Time:
How often a part or product is completed by a process. (or: the time taken for an operator to go through all his/her work elements before repeating them.)
C/T
• Cycle time includes all processes VA & NVA• Cycle time is measured by tracking it with a stop watch• We match the cycle time to the customer takt time• The process is “under control” if the cycle time is consistent
Standard Cycle Time
© BMA Inc. 2009. All rights reserved.
• Crew size - the number of people in the cell or operation required to produce to the cycle time recorded on the Value Stream Map
• # of cells = the number of cells running in parallel. Similar cells, working on the same products and performing the same process step.
Crew size = 5
# of cells = 1
Crew size and number of cells
© BMA Inc. 2009. All rights reserved.
Calculate the Capacity for the Machine Shop
Supplier Customer
Kanban
Shipping
S&OPDemand ForecastsPurchase Forecasts
Order
Supplier Customer
ShippingShippingAssemblyAssemblyAssemblyAssemblyAssemblyWelding
3,000 per Month
MachineShop
MachineShop
MachineShopMachineShop
MachineShop
MachineShop
MachineShop
Qty = 30,000C/T = 70sBatch = 1500Set Up = 10,800sScrap = 10%Rework = 20%Downtime = 15%Inspection = 10%Insp Time = 120s# cells = 8Crew Size = 4# of people = 34Shifts = 1
Qty = 15,000C/T = 180sBatch = 600Set Up = 1200sScrap = 5%Rework = 10%Downtime = 5%Inspection=100%Insp Time = 30s# cells = 5Crew Size = 1# of people = 10Shifts = 2
Qty = 3,000C/T = 210sBatch = 20Set Up = 600sScrap = 0%Rework = 10%Downtime = 0%Inspection=100%Insp Time = 60s# cells = 2Crew Size = 5# of people = 10Shifts = 1
Qty = 3,000C/T = 120sBatch = 1Set Up = 0sScrap = 0%Rework = 2%Downtime = 0%Inspection=0%Insp Time = 0s# cells = 1Crew Size = 1# of people = 1Shifts = 1
DATA BOXES
© BMA Inc. 2009. All rights reserved.
Step 1. Calculate the Total Available Employee Time(#employees x #days x Labor Hrs per shift)
Step 2. Calculate the Employee Productive Time(Qty per Month x Cycle Time x Crew Size)
Step 3. Calculate the Emp. Productive Capacity Percentage.(Employee Productive Time / Total Available Time)
Step 4. Calculate the change-over time, scrap & rework time, downtime, inspection time. C/O = (quantity/batch size) x Change-over timeScrap/rework = (Qty produced / (1- (scrap + rework %) ) * (scrap + rework%) x Cycle Time x Crew SizeD/T = Downtime% x Total Available TimeInspection= (Total produced + scrap/rework) x Inspection % x Inspection timeOver-production = OP Qty x Cycle Time * Crew Size5S & Clean-up = 5S Time x #Employees x #daysMeetings = Meeting Time x #Employees x #daysTPM = TPM Time per day * #days
Step 5. Calculate the Total Non-Productive TimeSum of Step 4
Step 6. Calculate the Emp. Non-Productive Capacity PercentageTotal Non-Prod Time / Total Available Time
Step 7. Calculate the Emp. Available Capacity Percentage. 100% - (Prod. Capacity + Non-Prod Capacity)
CELL DESCRIPTIONMachine
Shop
Employee Productive Capacity 46%Employee Non-Productive Capacity 47%
Employee Available Capacity 8%Quantity Required per Month 30000Quantity Produced in the Cell 31500
Over Production 1500Unit of Measure Units
Employee Cycle Time (per Crew) 70Maximum Pieces per Hour (per Crew) 51
Internal Change Over Time Sec 10800External Change-Over Sec 0
Labor Hours per shift 7.50# Shifts per day 1
Average Batch Size 1500Number of Change-Overs 20
Scrap Rate 10%Rework Rate 20%
Scrap/Rework Quantitiy 13,500Downtime % 15%Inspection % 10%
Inspection Time Sec 1205S & Clean Up Time per Day 600Meetings & reporting per day 600
TPM Time per Day 1800Other Non-Productive - User defined 0Other Non-Productive - User defined 0
Crew Size 4# cells 8
Number of Employees 34
Days per month 20
Calculate the employee capacity
© BMA Inc. 2009. All rights reserved.
Machine Shop Capacity - employees
7%Available Capacity
100% - (46% + 47%)Step 7
47%Non-Productive Percentage
8,562,000 / 18,360,000Step 6
8,562,000 secTotal Non-Productive TimeStep 5
216,000 sec3,780,000 sec2,754,000 sec540,000 sec420,000 sec408,000 sec408,000 sec36,000 sec
Non-Productive TimeChange-Over: 20 * 10,800
Scrap/ Rework: (31,500 / 70%) * 30% * 70 * 4Downtime: 15% * 18,360,000
I nspection Time: (31,500+13,500) * 10% * 120Over production: 1500 * 70 * 45S & Clean Up: 600 * 34 * 20
Meetings & reports: 120 * 34 * 20TPM: 1,800 * 20
Step 4
46%Productive Percentage
8,400,000 / 18,360,000Step 3
8,400,000 secProductive Time30,000 * 70 * 4
Step 2
18,360,000 secTotal Employee Time
34 * 20 * 7.5 *3600 secondsStep 1
7%Available Capacity
100% - (46% + 47%)Step 7
47%Non-Productive Percentage
8,562,000 / 18,360,000Step 6
8,562,000 secTotal Non-Productive TimeStep 5
216,000 sec3,780,000 sec2,754,000 sec540,000 sec420,000 sec408,000 sec408,000 sec36,000 sec
Non-Productive TimeChange-Over: 20 * 10,800
Scrap/ Rework: (31,500 / 70%) * 30% * 70 * 4Downtime: 15% * 18,360,000
I nspection Time: (31,500+13,500) * 10% * 120Over production: 1500 * 70 * 45S & Clean Up: 600 * 34 * 20
Meetings & reports: 120 * 34 * 20TPM: 1,800 * 20
Step 4
46%Productive Percentage
8,400,000 / 18,360,000Step 3
8,400,000 secProductive Time30,000 * 70 * 4
Step 2
18,360,000 secTotal Employee Time
34 * 20 * 7.5 *3600 secondsStep 1
© BMA Inc. 2009. All rights reserved.
Machine Shop Capacity
EMPLOYEECAPACITY
Cell output is driven by Employee
Time rather than Machine Time.
There is more machine capacity
than employee capacity
CELL DESCRIPTION
Employee Productive CapacityEmployee Non-Productive Capacity
Employee Available CapacityQuantity Required per Month
Quantitiy Produced in the CellOver ProductionUnit of Measure
Employee Cycle Time (per Crew)Maximum Pieces per Hour
Internal Change Over Time SecExternal Change-Over Sec
Labor Hours per shift# Shifts per day
Average Batch SizeNumber of Change-Overs
Scrap RateRework Rate
Scrap/Rework QuantitiyDowntime %Inspection %
Inspection Time Sec5S & Clean Up Time per DayMeetings & reporting per day
TPM Time per DayOther Non-Productive - User definedOther Non-Productive - User defined
Crew Size# cells
Number of Employees
Days per month
CELL DESCRIPTION
Machine Productive CapacityMachine Non-Productive Capacity
Machine Available CapacityQuantity per Month
Quantitiy Produced in the CellOver ProductionUnit of Measure
Machine Cycle TimeChange Over Time
Machine Hours per Shift# Shifts per day
Average Batch SizeNumber of Change-Overs
Scrap RateRework Rate
Scrap/Rework QuantitiyDowntime %
5S & Clean Up Time per DayMeetings & reporting per day
TPM Time per DayOther Non-Productive - User definedOther Non-Productive - User defined
# Machines per CycleNumber of Machines
Days per month
MACHINECAPACITY
Machine Shop
31%35%33%
30,00031,5001,500Units
3010800
81
150020
10%20%
12,85815%600120
9,60000210
20
Machine Shop
46%47%8%
30000315001500Units
7051
108000
7.501
150020
10%20%
13,50015%10%1206006001800
0048
34
20
© BMA Inc. 2009. All rights reserved.
Capacity Calculations when you have Multiple Product FamiliesCalculate the weighted average of the cycle time, change-over, etc.
WEIGHTED AVERAGE CALCULATION
PRODUCT FAMILY TOTALProduct Family A
Product Family B
Product Family C
Quantity Required per Month 10,500 2,500 5,000 3,000Employee Cycle Time (per Crew) 131 240 120 60
Total Cycle Time 5,520,000 2,400,000 2,400,000 720,000 0 0 0 0 0Internal Change Over Time Sec 8,293 10,800 5,400 10,800
External Change-Over Sec 0 0 0 0Average Batch Size 375 400 400 400
# Batches 28 7 13 8Total Internal 928,800 302,400 280,800 345,600
Total External 0 0 0 0Total Change Over Time 928,800 302,400 280,800 345,600
Scrap Rate 13% 20% 10% 10%Rework Rate 18% 20% 15% 20%
Total Scrap 1,514 625 556 333 0 0 0 0 0Total Rework 2,257 625 882 750 0 0 0 0 0
Total Scrap & Rework 3,771 1,250 1,438 1,083 0 0 0 0 0Inspection % 10% 10% 10% 10%
Inspection Qty 1,050 250 500 300 0 0 0 0 0Inspection Time Sec 91 120 60 120
Total Inspection Time 384,000 120,000 120,000 144,000 0 0 0 0 0Crew Size 4
© BMA Inc. 2009. All rights reserved.
Value Stream Capacity
• Value Stream demand = 3,000 units/month
• Takt Time = 180 sec• Average product has
5 welded sub-assy• Average sub-assy
has 2 machined components
• Machine Shop makes 30,000 items
• Welding Shop welds 15,000 sub-assy
• Assembly assembles 3,000 units
• Shipping ships 3,000 units
CELL DESCRIPTION
Employee Productive CapacityEmployee Non-Productive Capacity
Employee Available CapacityQuantity Required per Month
Quantitiy Produced in the CellOver ProductionUnit of Measure
Employee Cycle Time (per Crew)Maximum Pieces per Hour
Internal Change Over Time SecExternal Change-Over Sec
Labor Hours per shift# Shifts per day
Average Batch SizeNumber of Change-Overs
Scrap RateRework Rate
Scrap/Rework QuantitiyDowntime %Inspection %
Inspection Time Sec5S & Clean Up Time per DayMeetings & reporting per day
TPM Time per DayOther Non-Productive - User definedOther Non-Productive - User defined
Crew Size# cells
Number of Employees
Days per month
Maximum Capacity is3,000 units because
Machine Shop can only make 30,000 parts
Machine Shop
Welding Shop Assembly Shipping
46% 50% 58% 67%45% 26% 10% 4%9% 24% 32% 29%
30000 15000 3000 300031500 15000 3000 30001500 0 0 0Units Units Units Units
70 180 210 12051 20 17 30
10800 1200 600 00 0 0 0
7.50 7.50 7.50 7.501 2 1 1
1500 600 20 120 25 150 3000
10% 5% 0% 0%20% 10% 10% 2%
13,500 2,648 334 6215% 5% 0% 0%10% 100% 0% 0%120 30 0 0600 600 600 600120 120 120 1201800 0 0 0
0 0 0 00 0 0 04 1 5 18 5 2 1
34 10 10 1
20 20 20 20