Equipment Focused Methods Flashcards
(99 cards)
1
Q
Why do we need methods for avoiding waste?
A
To get high productivity of resources (equipments and people) and adhere to the business plan where paybacks of investments are expected.
However: paybacks are not guaranteed. Thus, weak points must be identified.
2
Q
What are the two methods used in order to determine equipment weak spots?
A
Equipment Focused Methods and Human Focused Methods
3
Q
What is the purpose of Equipment Focused Methods? What are some methods of optimization?
A
To maximize the operational effectiveness of an equipment
Methods for optimization: Implementation of TPM Low cost automation SWCT ECTS Standard Principles Body in White & LCC Flexible work system
4
Q
What is the purpose of Human Focused Methods?
A
To maximize the operational efficiency of people
5
Q
What are the two possible steps in the Equipment Based Process?
A
Planning or redesign
Equipment based processes are being improved in terms of effectiveness in the planning phase of a new design as well as in reengineering in the context of TOS projects & activities.
6
Q
What is a New Design and what does it entail?
A
TOS Implementation of new processes
- Planning based on standards principles
- Application of Lean Conformity Check
- Station development workshop to check and confirm planning state
7
Q
What are the steps when approaching a redesign of a bottleneck in a process?
A
- Value stream mapping and bottleneck identification
- Detailed analysis on the bottleneck
- Definition and implementation of countermeasures
- Stabilization of implementations
8
Q
Value stream (analysis) in the equipment focused method is?
A
The basis of any equipment optimization
–a standard method for visualizing the entire process of a production including lead time as well as connection of material and information flow
–the visualization of waste and its sources in the overall process
–a common language when talking about the manufacturing process
–an objectification of the discussion about the necessary optimization through numbers, data and facts
9
Q
What are the steps of the Value Stream Process in Equipment Optimization Projects?
A
- Determine customer demands
- Draw process steps
- Collect process data
- Collect inventory data
- Determine external material flow
- Draw internal material and information flows
- Calculate throughput time and enter value creation time
- Weak points/findings out VSM analysis
10
Q
IT-tools support the creation of VSM
A
Interactive tool based on Excel for equipment:
- -Illustration of VSM
- -Cycletime of all equipment in overall process
- -Trend of downtimes
- -CT-Downtime Matrix
IT based solutions available:
–e.g. value stream modeler (www.ifakt.de)
Keep an eye out for this tool as well:
–MPS App (by Siemens)
11
Q
In context to equipment related processes, takt time is the basis for what?
A
- Deriving capacity by consideration of given processing time
- Balancing workload in automatized system to avoid bottlenecks
- Output management to see deviations in processing time from takt time
12
Q
Equipment Cycle Time is the sum of?
A
the sum out of primary (productive time) and secondary (part change time, positioning time, tool change time) processing time
13
Q
What happens in the primary equipment processing time?
A
a productive process is happening (parts are being machined).
14
Q
The secondary equipment processing time is a compound of which three “times”?
A
- part change time: the time that is needed to change parts on the machine
- positioning time: the time that is needed to reposition the machine or parts of the machine
- tool change time: the time that is needed to change a tool at the machine
15
Q
What is the Theory of Constraints?
A
- Every system has only one bottleneck at any one time
- The capacity of the system is determined by the bottleneck
- Optimization at a non-bottleneck is not purposeful and therefore waste
16
Q
The equipment capacity (production volume) is limited which three dimensions of losses?
A
- Usage- measurement is reduction
- - Unoccupied shifts
- - Breaks & maintenance - Effectiveness- measurement is reduction
- -Maintenance & technical downtime
- -Setting up
- -Idle time (Start-up / runout losses)
- -Cycle time losses
- -Rejects
- -Re-work - Machine cycle time- measurement is optimization
- - Primary processing time
- - Secondary processing time
17
Q
Which of the following is not an equipment dimension of losses? Line takt Usage Cycle Time Effectiveness
A
Line takt
18
Q
The identification of the bottleneck depends on
A
whether the line is a simple line or a complex line
19
Q
As opposed to a complex line, what is a Simple line?
A
- The interactions between machines are clear
- The complexity of machining is manageable
- Machines are not interlinked or only rigidly linked
- Operation oriented or standalone machining island
Bottleneck identification is based on: Expert opinion (balance between production, planning and maintenance)
20
Q
What does a Complex line mean?
A
- The interactions between machines are complex
- Flexible interlinked line, automated, with (dynamic) buffers, serial or parallel
Bottleneck identification is based on:
Simulation
OEE Monitor (based on Prisma data)
21
Q
If the bottleneck is not clearly visible, what is required?
A
detailed analyses are required
The interlink between equipment influences the dynamic, and thus output of the overall system
22
Q
What is a Rigid Interlink?
A
Rigid interlink= lifting bar
The Line Output Takt is calculable
It is determined by:
- the machine with the longest cycle time
- the line availability, the product of all individual availabilities
Line Availability: Aline = AOP10 x AOP20 x … x AOPn
Line Output Takt: Taktline - CTbottleneck / Aline
23
Q
What is an Elastic Interlink?
A
Elastic interlink= conveyer
Line Output Takt is not calculable.
It is determined by:
- -the machine with the longest cycle time
- -the line availability, which is not calculable
Line Output Takt: determinable through simulation
24
Q
What is Slack interlink?
A
Slack interlink=storage
The Line Output Takt is calculable.
It is determined by:
– the machine with longest average Output Takt
Output Takt by OP: TaktOPn= CTOPn / AOPn
Line Output Takt: Taktline = max(TaktOPn)
25
To identify a system‘s bottleneck, there are 3 proven methods available, depending on the system used. What are they?
1. Cycle time/machine downtime matrix (static)
2. Change-point-method (dynamic)
3. Active period method (dynamic)
26
Cycle time/machine downtime matrix (static)
- - The machine with the longest Output Takt is the bottleneck
- - Low demands on input data; possible to write out by hand or use of PDA eg. PRISMA
- - Not accurate with an elastic interlink, as there is no consideration for the dynamic in the system
Apply to rigid interlink and slack interlink
27
What is the Change-point-method (dynamic) with reference to bottlenecks?
- - The machine whose status changes from more output blocked to more input empty (starved) is the bottleneck
- - Reporting of logistical downtimes (starved, blocked), possible to write out by hand or use of PDA eg. PRISMA
- - Intuitive and easy to understand
- - No explicit predication
Apply to elastic interlink
28
What is the Active period method (dynamic)?
- - Most reliable and most advanced method
- - Machine with the longest mean active time is the Bottleneck
- - Inactive time: Logistical conditions
- - Active time: All other conditions such as automatic, malfunction, manual operation, etc…
- - Higher demand on data quality, namely data from PDA
Apply to elastic interlink
29
In reference to bottlenecks what does a Value Stream Analysis do?
In the context of the value stream analysis showing the stocks between the individual plants.
The bottleneck is the plant in front of which the workpiece stocks are highest.
Advantages:
easy data collection
Disadvantages:
Accuracy is guaranteed only if the buffer size is unlimited, otherwise there is no clear bottleneck determination
30
When referring to bottlenecks, what is the Change Point Method?
The inflection point method displays the sum of the logistical states "blocked" and "waiting" per system.
Bottleneck is the plant where a turn from "blocked" to "waiting" takes place and the sum of logistical downtime is lower than at the surrounding stations.
Advantages:
Consideration of the chaining
Disadvantages:
no statement about the other loss factors
several bottlenecks possible
Apply to elastic interlink- conveyor
31
Cycle time – Equipment Effectivness Matrix (CT-EE)- Bottleneck
Comparison of system failures (technical faults) and associated cycle times of each individual system. Possible bottlenecks are plants with the highest cycle time and/or low plant effectiveness (for linked systems, the logistical disruptions are taken out of the system).
Advantages:
quick identification of possible bottleneck machines and their loss factors
several bottlenecks possible
Disadvantage:
ignores the chaining and material flow
32
When determining a bottleneck, what is an Active Period Method?
The bottleneck is the station with the longest average active duration.
"Active” states can put other systems into a waiting state (machining, fault, repair, tool change, set-up). "Inactive" states are all waiting states of a system (blocked, waiting).
Advantage:
Consideration of all loss factors and the links
Disadvantage:
several bottlenecks possible
33
What is active machine condition?
operating
repairing
Incident/breakdown
manual mode (change over, tool change/replacement, maintenance, etc.)
34
Inactive machine condition
waiting for parts (starved)
| blocked (e.g. machine in front is down)
35
According to the Active Period Model, in a system with interlinked machines the bottleneck is...
the machine with the longest mean active time in the interval investigated:
- -consideration of all loss factors of the machines including interlink
- -multiple bottlenecks possible if mean active time shows no clear difference
- -Not applicable at slack/manual interlinks (machines are feeded manual)
Prerequisite is availability of data from all machines which are in scope by production data acquisition (e.g. PRISMA) and high quality of data.
36
Sources to get data from machine conditions
Production Data Acquisition (PDA) and Manual Records
37
Production Data Acquisition (PDA)
- - Use of automatic generated data from equipment e.g. WEB PRISMA
- - Equipment conditions are recorded with the time new conditions occur
- - Bases for Shopfloor Management and problem solving
Important:
- -Maintenance of data base (e.g. target cycle time ..) and operating calendar
- -Before usage of data a detailed validation of data and machine conditions is required – “is my measuring system capable?"
- - If no valid data from a PDA is available, manual records about machine conditions need to be carried out
38
Manual records (24h Analysis)
- - If no data from a production data acquisition system are available or not reliable, manual records of the machine conditions are required
- - Equipment needs to be observed in operation for a defined time
- - Records of machine conditions can be taken directly in a EXCEL to minimize effort for analysis
- - Manual records are time consuming and need detailed preparation and guidance of observers
39
Overall Equipment Effectiveness (OEE)
Overall equipment effectiveness (OEE) provides a view of the effectively used capacity of the machine or equipment for added-value activities based on the entire time available (365 days, 24 hrs. = plant operating time).
Application:
Evaluation of output capacity
Deriving measures for increase of utilization e.g. additional shift, production during breaks…
Long-term investigations
*includes planned losses
40
Equipment Effectiveness (EE)
Equipment effectiveness (EE) provides a statement of productivity of a piece of equipment or machine on the basis of the scheduled time allocated to production (e.g. depending on shift model).
Application:
Assess effectiveness of usage of equipment by production
Assess effectiveness of support functions e.g. maintenance
Short- and mid-term steering, e.g. in daily shopfloor management
*includes availability losses, performance losses, and quality losses
41
OEE Calculation Benefits
Increased transparency of output and losses at the bottleneck
Deriving of effective containment and countermeasures the eliminate losses
Increasing process stability and continuous flow
Aligned capacity planning and target out based on common calculation for planning and production
Communication between departments based on common calculation bases
42
OEE Calculation Targets
Production and planning use same figures and calculation base for capacity planning to set targets and identify losses
Standardized OEE/EE calculation bases for KPI’s and wording are applied in the whole organization
OEE is the bases for determination and assessing of production capacities
EE is applied in the shopfloor management
43
What are Planned Losses (utilization)?
Losses in detail
- -Planned downtimes for breaks
- -Employee meeting and worker information
- -standard communication & team meeting
- -planned maintenance & inspection
- -Unscheduled shifts
Impact factors
- Operating permit of plant
- labor management contract of plant
Detailed analysis
-Check possibilities to reduce unscheduled shifts
Data base & tools
- -shift calendar
- -labor management contract
44
What are Availability Losses?
MTTR & Mean Time Between Failure (MTBF)
Spaghetti Diagram
SWCT- Standard work combination table
Excel Tool in a Set Up Workshop
Losses in detail
- -Technical errors & repair
- -Replacement of worn tools
- -Change set up for other part variant
45
What are Performance Losses?
Tally Charts
PDA System Data
Losses in detail
- -Cycle time losses (reduced speed)
- -Idle time (short stops, warm-up losses, etc.)
46
Quality Losses
Losses in detail
- -Reworking of parts
- -Rejecting of parts
47
Mean Time to Repair (MTTR)
MTTR= Total failure time/number of failures
Use in maintenance areas
Total Downtime per shift is the sum of time in which the machine is waiting to be repaired/ repaired.
MTTR is measured for each machine separately.
Number of Breakdowns within the shift.
48
Mean Time Between Failure (MTBF)
Number of Repairs within the shift.
Used in maintenance areas
Net-Operating Time is the sum of time in which the machine is running without breakdown/ repair.
MTBF is measured for each machine separately.
49
Takt Time Tool Box approach
cycle time losses can be analyzed and potentials derived
1. Analysis of current situation
2. Potentials in process to reduce primary processing time
3. Potentials in movement to reduce secondary processing time
4. Potentials in change over to reduce secondary processing time
5. Potentials in PLC code to reduce primary and secondary processing time
Potentials in PLC Hard and software to reduce primary and secondary processing time
50
Programmable Logic Controller (PLC) Cycle Time Analysis
Target
Cycle time analysis for equipment with Programmable Logic ControllerPLC (NC, SPS...)
Analysis of time bricks based on time acquisition within the PLC
Tools
Data interface to PLC (data in readable format for Excel)
Excel for data analysis (NCTA+ or similar tools)
Procedure
Server connects to PLC of specific equipment for sampling information from ongoing process (if no server – use e.g. USB interface of PLC)
Analysis of sampled data in specific categories (primary and secondary processing times)
Creation of visualizations
51
What are the targets of Manual Eye & Stop Watch?
Target
Observation and time sampling of process steps
Observation of set ups strategy, interruptions & waiting times, tool and part exchange within the cycle, speed of operations and movements
Tools
Stop watch
Procedure
Defining observation point
Define sub criteria's (e.g. positions of tool) for stopping process steps
When Machining with cooling fluids: use finished part and produce again with out fluid – clean windows
Repeat time sampling
Documentation and evaluation of data in EXCEL
52
Video Analysis
Target
Capturing of process and time of single steps
Recognition and measuring of interruptions and waiting times in process
Recognition of movement losses
Tools
Video Camera (e.g. GoPro)
Video player
MS Excel for Analysis & documentation
Procedure
Observation of process and definition of camera’s position
Set up of camera
Recording of process when cooling fluid used: use finished parts and run process without cooling fluid
Analysis of video filed and transfer time bricks into Excel
53
What are the 6 equipment effectiveness losses?
1. losses due to maintenance and technical downtime
2. losses due to idling and short stoppages
3. losses due to reject and rework
4. losses due to change over and set up
5. losses due to increased cycle times
6. losses due to start-up/shut-down
54
What is TPM?
TPM stands for “autonomous, planned and preventive maintenance”
high availability through preventive maintenance of machines and plant, in short: “Total Productive Maintenance”
55
TPM is the Continuous improvement of equipment availability by avoiding sources of loss, such as
1. Plant breakdown
2. Long changeover and set-up operations
3. Difficulties with start-up
4. Wear
5. Inadequate operator training
56
What are the five pillars considered in the TPM?
1. Autonomous maintenance
2. Maintenance strategy
3. Targeted equipment/installation improvement
4. integration of maintenance at early stage in equipment installation planning
5. spare part management
57
When talking about the Five TPM Pillars what are the differing effects on the effectiveness and efficiency?
Efficiency
"Doing things right"
The input decreases while the output stays the same.
Effectiveness
"Doing the right things"
The input stays the same while the output increases.
58
Quick Change Over (SMED)
When different part variants are produced, in many cases the equipment set up needs to be changed for the requirements of the successor variant.
**reduced equipment availability
SMED stands for "Single Minute Exchange of Dies“ (exchange of jigs and fixtures in the single-digit minute range)
59
Change over or change over time is defined to be?
the time that is measured from the last OK part of a variant produced in the specified cycle time to the first OK part of the new variant produced in the specified cycle time.
Change over in this case includes changing products and changing tools. During change over and set up, the equipment is not working even if it is not defective.
The biggest loss appears normally through change over, set up and adjustment of the equipment
60
ECCS Method
Eliminate- Discontinue change over steps directly or after technical changes
Combine- Parallelization of change over steps
Change/reduce- Create "logical" sequences; Transfer logical sequence into change over procedures
Simplify- standardization of procedures
61
What belongs to the five pillars of TPM?
budget for spare parts
operators repair equipment in case of minor break-downs
62
What is total downtime per shift?
The sum of time in which the machine is waiting to be repaired
63
What is net-operating time?
The sum of time in which the machine is running without breakdown or repaire
64
Small and intermediate stops can be captured by?
Tally charts
In order to save time, the intermediate stops tally sheet is going to be at the working place of the team member
For every stop below 3 minutes a dash is made according to the appropriate failure code
65
What two types of losses are in OEE?
Chronic and sporadic
66
Chronic losses are?
recurrent failures that become "habitual"
To reduce chronic losses or to reduce them to zero under optimal conditions, Total Productive Maintenance provides assistance through maintenance and the associated continuous improvement process.
67
Sporadic losses are?
sudden casualties are often remedied by fire-fighter actions or task force.
68
When does the biggest loss usually appear?
change over, set up, or adjustment of the equipment
69
Internal change over procedure?
Scope of work to be performed in the event of machine standstill
i.e. exchange of machine parts
70
External change over procedure?
Scope of work to be performed in operation/restart of the machine
- checking of tools
- receipt of raw materials
- receipt or return of tools
- positioning of crane
- pre-setup of equipment
If batch sizes are getting smaller, external change over procedure can become the limiting factor.
71
What change over procedure will be the limiting factor if batch sizes get smaller?
External chang over
72
What is standardize work combination table (SWCT)?
To standardize manual interaction between operator and equipment
Interaction of operator and machine can appear in each cycle, when loading/unloading work piece or changeover/setup processes
73
What possibilities allow to combine operations?
1. multi-purpose like machine center
2. Tools with multiple edges
Parallelization of change over steps
Combination of two sequential steps in one parallel procedure
Goal: Both hands are in use
74
TPM implementation follows a 4 step approach? What are they?
1. Evaluations of existing maintenance
2. Evaluation of organization prerequisites
3. Prioriziation of starting points
4. TPM implementation plan
75
Which dimensions are considered in the priorization of the Starting Points?
1. evaluation is performance diagnosis
| 2. effect to OEE target (derived by OEE analysis)
76
TPM within Daimler Trucks is implemented and sustained according to what level model?
4
77
TPM Level 1
1. Create TPM basis
-TPM training
-identify TPM relevant machines
basic cleaning
-create maintenance plans
In the beginning TPM focuses on bottleneck machines or machines with high risks.
78
TPM Level 2
2. Living TPM
- Determine time requirements
- execute maintenance plans
- documentation of failure by production staff
- supervision by management
- audit required for awarding of Level 2
Objectives / Advantages:
- Evaluation of time need
- execute maintenance plans
- documentation of failures by production staff
- supervision by executive manager / OU manager
Audit to award stage 2 is needed
79
TPM Level 3
3. Optimize TPM
Optimization of maintenance plans (content and cycles)
Audit to award stage 3 is needed
After 6 months of living and optimization of the implemented TPM audit for Level 3 can be conducted
Continuous evaluation of intermediate stops and breakdowns for optimization of TPM plans
80
TPM Level 4
4. Maintenance with production
Increase technical availability by reducing response time
audit required for awarding of Level 4
Maintenance with production is the following step to an autonomous maintenance – audit after 6 months
Operators take over small & defined electric. & mechanical maint. tasks
81
Who is the driver of TPM?
The driver of the TPM process is the respective Production OU
82
What is the objective of the TPM audit?
to examine the implementation of TPM values at individual machines (machine and its chip conveyors, loaders, etc.) and the general conditions in the surrounding environment.
The auditor will visualize achievement of an audit level by means of an adhesive label on or next to the machine. The label will show the date of the audit (wipe resistant due to indentations).
83
TPM Production Sup
* responsible for execution of maintenance plans
| * ensures timely execution of the defined maintenance scope
84
TPM MX Sup and Engineers
assist with execution of the maintenance plans
85
TPM Officer
• overall responsible for methodology, process control and audit
86
TPM "Godfather"
responsible for specified machines
87
TPM Maintenance
responsible for producing maintenance plans
88
ME Planner responsibility in TPM
new procurement of TPM-compatible machinery
89
For a given operating time, the production volume of a specific equipment is distinguished by what?
its cycle time and effectiveness
90
Bottleneck determination methods include?
1. Value stream analysis
2. Change-point method
3. Cycle time, EE matrix
4. Active period method
91
Which machine conditions are active respectively?
1. manual mode
2. operating
3. incident/breakdown
4. repairing
92
Overall Equp Effectiveness (OEE)
= (number of goods*target CT)/(24*#of days in review)
93
Equip Effectiveness (EE)
=(number of goods*target CT)/(busy time)
94
In context to equipment related processes takt time is the basis for ...
1. Deriving capacity by consideration of given processing time
2. Balancing workload in automized system to avoid bottlenecks
3. Output management to see deviations in processing time from takt time
** Take time is the heartbeat of production
95
Cycle time is the sum of what?
primary and secondary processing times
**In the primary processing time value is added.
In the secondary processing time no value is added.
96
What times does Cycle Time include?
1. parts change time
2. positioning time
3. tool change time
4. productive time (primary processing time)
97
What equipment processes are necessary to build a truck?
1. Machining
2. CIW
3. Paint Shop
4. Foundry- factory that produces metal castings
98
What are considered external change over procedures?
1. checking of tools
2. Receipt of raw material
3. return of tools
4. positioning of crane
5. pre-setup of equipment
99
What would be considered an internal change over procedure?
1. exchange of machine parts
