Download Understanding Production Concepts: Blocking, Starving, Bottleneck, Pacing, and More and more Quizzes Production and Operations Management in PDF only on Docsity!
Buffer
triangle shape can be within an activity and represents the output of one activity (WIP) is placed prior to being used by a downstream activity.Holding Inventory TERM 2
Blocking
DEFINITION 2 when a flow unit must stop and wait because there is no place to put it (or activity is not ready for it) TERM 3
Starving
DEFINITION 3 when an activity cannot work because there is no input available.if an employee is waiting and no input is available the employee may have to remain idle until the next unit arrives TERM 4
Bottleneck
DEFINITION 4 Constraintfactor that limits productionoccurs when the limited capacity of a process causes work to pile up or become unevenly distributedSlowest activity (longest cycle time)Scarcest resources (usually material or people)Blocking occurs before (upstream from) a bottleneckstarving occurs after (downstream from) a bottleneck TERM 5
Pacing
DEFINITION 5 this is when you starve the bottleneck basically. You hold back producing so that your item can move right into the bottleneck and out.converts blocking into starving
Theoretical Flow Time
Rush order flow timethe time it takes for a unit order to go through the process from beginning to end without any waiting TERM 7
Cycle Time
DEFINITION 7 this is determined by the bottleneckaverage time between completion of successive units (often confused with throughput time)some define it as the minimum time between completion of successive units but be careful how it is definedActivity Cycle Time: no starving, blocking, downtimeProcess Cycle: accounts for waiting TERM 8
FR, TR, TC
DEFINITION 8 flow rate, throughput rate, or theoretical capacityaverage output per unit of time, assuming no yield losses or downtime (full utilization)activity flow rate- is unconstrainedprocess flow rate is determined by the bottleneck TERM 9
TT, FT, LT
DEFINITION 9 throughput time, flow time, lead timeaverage time for a unit to move through a process including any waitingactual measure depends on how the process is paced TERM 10
Utilization
DEFINITION 10 the percentage of time (or other resource) spent actually working on the product or performing the serviceTime Activated/Time Available
Set-up Time
Fixed TimeTime is required to set up or change over a machine or resource to make it ready for processingnormally "fixed" invariant vs the number of units in the batch or production lotSometimes used to refer to any and all fixed time components of activity duration TERM 17
Activity
Duration
DEFINITION 17 fixed time+variable timeset-up time + run time TERM 18
Steady State
DEFINITION 18 once a process has been running for a period of time it reaches a steady stateinflow=outflow TERM 19
CT
DEFINITION 19 average time between completing successive units TERM 20
R
DEFINITION 20 average flow rate or capacity
T
average time for a unit to flow through a process TERM 22
I
DEFINITION 22 Average WIP inventory TERM 23
Flow Rate
DEFINITION 23 R= (1)/(CT) TERM 24
Average Inventory
DEFINITION 24 Average Flow Rate * Average Flow Time TERM 25
WIP Inventory
DEFINITION 25 Throughout Rate * Throughput Time
pacing does nothing
cycle timecapacity/Rate TERM 32
Steady State
DEFINITION 32 "Average"in flow = outflow TERM 33
start up
DEFINITION 33 fixed set up timeinflow > Outflow TERM 34
Shut down
DEFINITION 34 outflow > inflow TERM 35
Two processes in
parallel
DEFINITION 35 improved: Theoretical flow time, throughput time, WIP Inventoryunchanged: process cycle time, capacity or rate, utilization, cost
split (2) bottleneck
improved: cycle time, capacity or rate, utilizationunchanged: theoretical flow time, throughput timeworse: WIP inventory, cost TERM 37
two processes in parallel in
succession
DEFINITION 37 improved:cycle time, capacity or rate, utilizationunchanged: theoretical flow time, throughput timeworse: WIP inventory, cost TERM 38
Two completely separate processes
DEFINITION 38 improved:cycle time, capacity or rateunchanged: utilization, theoretical flow time, throughput timeworse: WIP inventory, cost TERM 39
Lean
DEFINITION 39 improve efficiency by decreasing waste TERM 40
Theory of Constraints
DEFINITION 40 increase throughput by managing bottlenecks
3 approaches to quality
- inspect in quality check results before they leave the company2. build in quality check process performance along the way3. design in quality choose the right goals/specifications TERM 47
costs associated with lack of quality
DEFINITION 47
- detection/appraisal costs2. prevention costs3. failure costs TERM 48
Six Sigma
DEFINITION 48 eliminate defects in products and processes by reducing variationlatest incarnation of process improvement approaches that rely on scientific methods of data gathering, experimentation, and hypothesis testing TERM 49
Six Sigma Cycle
DEFINITION 49 DMIACDefine: customers and prioritiesMeasure: Process and its performanceAnalyze: Causes of defectsImprove: By removing causes of defectsControl: By maintaining qualityothers: Design Build Test, Plan Do Check Act, Observe Orient Decide Act TERM 50
Process Improvement Tools
DEFINITION 50
- Descriptive Tools: flow chart, pareto chart, histogram2. Diagnostic Tools: cause and effect diagram, scatter plots3. Monitoring and control tools: Statistical Process Control
Fish bone Diagram
isolate one specific defect, problem, or conditionexcellent tool for maintaining structure in brainstorming TERM 52
5 Whys
DEFINITION 52 brings you to the real root of a cause TERM 53
Check Sheet
DEFINITION 53 used to track defects TERM 54
Multi Vari Charts
DEFINITION 54 Positional Variation: Variation within batchesCyclical Variation: Variation between batchesTemporal Variation: Variation over time TERM 55
Pareto Chart
DEFINITION 55 Cumulative Percent Curve track defects
Mistake Proofing
Shingos Argument: statistical quality control methods do not prevent defects (helping people avoid errors)Poka-Yoke: checklists, tooling, visual cues (prevent from making errors) TERM 62
ISO 9000
DEFINITION 62 Standards agreed upon by the international organization for standardization TERM 63
Benchmarking
DEFINITION 63
- Identify processes needing improvement2. Identify a firm that is the world leader in performing the process3. Contract the managers of that company and make a personal visit to interview managers and workers4. Analyze data and identify best practices5. Transfer best practices to local processes TERM 64
Five Principles of Lean
DEFINITION 64
- Specify value in terms of the ultimate customer2. Identify all of the actions required to get a product or service to that customer3. Create continuous, single-piece flow wherever possible4. Only flow product when a customers pulls it5. Seek perfection through an environment of continuous improvement TERM 65
Seven Wastes in Operations
DEFINITION 65
- Waste from overproduction2. Waste of waiting time3. Transportation waste4. Inventory waste5. processing waste6. waste of motion7. waste from product defects
Lean has a big reliance on?
respect for peoplelevel payroll, profit sharing, subcontractor unions TERM 67
JIT Demand Pull Logic
DEFINITION 67 Vendor->Fabricator-->Sub-assembly--> Final Assembly--
Customer TERM 68
JIT Production What it is?
DEFINITION 68 Management philosophypull system through the plant TERM 69
JIT Production What it does?
DEFINITION 69 Attacks wasteexposes problems and bottlenecksachieves streamlined production TERM 70
JIT Production What it requires?
DEFINITION 70 employee participationindustrial engineering/basicscontinuing improvementtotal quality controlsmall lot sizes
Liposuction vs. Exercise
L: remove non-value activities; demolish and old activity for newE: improve the value added by processes, ensuring activities and processes produce the right deliverables TERM 77
Working Harder
DEFINITION 77 effort * capability= Actual Performancetime: working increases and improving decreasescapability: down over timeActual performance: initial increase then decrease over time TERM 78
Working Smarter
DEFINITION 78 effort * capability= Actual Performancetime: working decreases and improving increasescapability: rises over timeActual performance: initial decrease then increase over time
