Flashcards
Flashcards OM: Process Thinking
Flashcards do conjunto (42)
- 1A simple process example (concrete block casting machine) (turbocharger castings)1. Prepare materials
2. Cast materials into mould
3. Release cast objects from mould
4. Transport cast objects - 2ProductivityOutput from the operation divided by the input to the operation
- 3Variety and Volume trade off1. Generally, the higher the volume produced by a business operation, the less variety there is in the products made
2. Ranging from 'project' and 'jobbing' to 'mass' or 'continuous' production systems - 4High variety and low volume to low variety and high volume1. One-off
2. Jobbing
3. Batches
4. Mass production
5. Continuous production - 5Work contentTotal amount of work required (in minutes)
- 6Throughput timeTime for a unit to move through a process
- 7Cycle timeAverage time between units of output emerging from a process
- 8Work in progress (WIP)1. The number of units within a process waiting to be processed further
2. Represents money tied up in part finished goods that need storing, moving about etc
3. Low WIP is more efficient - 9Little's law1. Throughput time = Work in progress x cycle time
2. % throughput efficiency = Work content x 100 x throughput time - 10How to improve a process efficiency1. Reduce time to complete the operation
2. Have fewer items 'in' process at any point in time - 11The ideal process1. Materials arriving at operation stage and be processed straight away
2. Once completed, the output will be passed to the next stage of production or customer - 12Process variability1. Ideal processes are impossible
2. Work to be processed may arrive at the stage either early or late
3. The duration of the operation may vary from one cycle to the next - 13Optimising by reducing waiting timeWill lead to lower machine utilisation as the machine is sometimes be waiting for work to arrive
- 14Supply network1. Some processes will be done by suppliers
2. Some will be subcontracted
3. Many of the process stages in a whole supply network will have excess work in progress and underutilised assets
4. First tier suppliers have an immediate relationship with the customer, so might manage better their utilisation and WIP
5. Inefficient process stages in your organisation may be outsourced, however, consider if the 'know how' in the process is of strategic importance to your company - 15Capacity management1. Each process stage or operation will have an optimum capacity
2. However, production capacity tends to be added in 'chunks' such as new machines
3. This means that often production runs at less than theoretical optimum levels - 16Smoothing1. Creating inventory allows the purchases of additional capacity to be delayed slightly
2. Creating inventory allows the company to cover breakdowns, maintenance periods, holidays etc
3. Inventory helps smooth peaks/troughs in demand
4. Caution: inventory can hide problems from view - 17Capacity-adding decisions1. Should capacity lead or lag demand?
2. Short term demand can be met with overtime
3. New capacity takes time to order, install and train staff to operate
4. To make a decisions on when to add capacity you need a forecast of demand - 18Forecasting1. The engineer needs to know how much of a product is required
2. Usually expressed as an output rate of completed product
3. This forecast information needs to come from assessing market demand - 19Forecasting demand1. If the product is a basic commodity with little innovation, then forecasting demand may follow simple rules of what happened in the past.
2. If the product is in a growing market, as innovative or not yet launched demand forecasting will be more difficult - 20Quantitative forecasting1. Use sales records for previous trading weeks
2. Consider seasonal variations - look at sales pattern this time last year
3. Consider growth rate in market
4. Make a forecast
5. Check actual sales and adjust model - 21Moving Average Forecasting1. Take (say last 4 weeks) average calculated on a rolling basis
2. Gives equal weight to all previous periods
3. Ignores information outside the data period considered - 22Casual models1. Causal models try to link the demand to other factors that are known or can be estimated
2. For example ice cream sales will tend to increase when temperatures are higher
3. Obviously several factors are at work so a more accurate forecast model will take into account these additional factors - 23Qualitative forecasting1. Ask the opinions of experts
2. Describe scenarios low, mid, high
3. Delphi questionnaire - experts fill in their answers, then participants view all answers, finally participants are given the opportunity to modify their views
3. How accurate does the engineer require the demand estimate to be? - 24Forecasts in short/long term1. A power supply company needs to have an accurate model to help forecast peaks in demand for electricity over the next 24 hr
2. The same company wish to predict energy demand in 10 years time so that new generating capacity may be planned and brought on stream
3. Different forecasting tools are needed for each task - 25Consequences of incorrect forecasting1. If the demand is higher than forecast the goods will be out of stock and customers may defect to alternative products
2. If the demand is lower than forecast, production overhead will be high relative to units manufactured, goods may be made to stock, goods may have to be discounted to increase the sales volumes - 26Enterprise Resource Planning1. Planning ahead for whole business
2. The planning starts with financial targets expected for the year ahead
3. Push based system
4. Time phases plans
5. Complex centralised computerised system drives Master Schedule
6. Bill of Materials and Stock Record must be accurate
7. System can become unstable if lead times vary - 27Bill of Materials1. Create a bill of materials for each product variant
2. Add up each BoM x quantity forecast
3. Create a master production schedule - 28Master Production Schedule1. Purchasing - what to buy in and when to place orders
2. Production - what to make and when
3. Marketing/sales - What to promote/sell
4. HR - who to recruit, when shifts run, when holidays may be taken
5. Managers - when new products may be introduced - 29After Master Production Schedule1. What was actually made?
2. What finished goods stocks are held?
3. What firms orders have been received?
4. What still needs to be manufactured to fulfil these order?
5. What finished goods are 'available to promise' to a potential customer
6. Keep feeding the information forward and adjust plan - 30ERP impacts1. Integration across all parts of the business without duplication of information
2. Communication - visibility about what is happening in all parts of the business
3. Customer - supplier communications accurate and timely along supply chain - 31ERP implementation1. Integreate existing system? Adapt software to way things are done now?
2. Install all new system? Adapt way things are done to the new system
3. Essential to train staff how to use the new system - 32Just in time (JIT)Consideration of waste
- 33Consideration of waste1. Waste should be avoided. It makes the process less efficient and less profit is made
2. Waste is any activity that is not adding value to the product - 34Types of waste1. Over production
2. Waiting time
3. Transportation waste
4. Inventory waste
5. Processing waste
6. Waste of motion
7. Waste from product defects
8. Wasted energy - 35Just in Time aims to......Meet demands instantaneously with perfect quality and no waste
- 36Equipment utilisation1. High individual equipment utilisation might not be leading to overall process efficiency
2. An over- producing stage can build up surplus inventory in the manufacturing system - 37Throughput time1. Time how long it takes for an assembly to pass through the production environment
2. Then, record the times when the assembly is actually being worked on - this is the time when value is being added - 38Value Stream Mapping1. Identify the value stream
2. Map the physical process stages
3. Map information flowing to enable process to work
4. Improve the map
5. Implement changes
6. Monitor and feedback - 39People Factors1. Kaizen - continuous improvement towards objectives
2. Discipline - standard of work
3. Flexibility - expand responsibilities and extend individual capabilities
4. Autonomy - give staff the responsibility to measure, record and stop the process if they spot a problem
5. Quality of working life - job security, contribute to company
6. Creativity - motivation to improve things - 40Improvement techniques1. Design components for ease of processing
2. Use simple, repetitive processes that can be learnt, improved, refined
3. Use several small simple machines - simultaneous production, cover for breakdowns, lower investment costs, machines easier to move to where needed
4. Andon light - signals to everyone the status of the system
5. Layout for smooth flow of both the product and information
6. Co-locate workstations
7. Keep operators in sight of each other and their machines
8. U shaped lines allow easier movement between machines by operators
9. Total productive maintenance (TPM) - operators maintain their own machines and spot snags before a breakdown occurs - 41Kanbal 'pull' signal1. Kanban is a card or signal to pull materials through process
2. Can be a bar-coded card, ball, empty crate, marked out space on production area floor
3. Move kanban - pick part from inventory
4. Production kanban - make new inventory
5. Vendor kanban - signal to supplier to send materials/parts to production stage - 42Levelled scheduling - Heijunka1. Heijunka - over a time period the parts mix and volume are fairly even
2. Make small batches of most parts every day
3. Establish a regular routine of daily production
4. Frequently change over tooling to balance outputs from process
5. Runners - parts produced frequently
6. Repeaters - parts produced regularly but at longer time intervals
7. Strangers - parts produced irregularly
8. Synchronise to production drumbeat
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- Bachelors Operations Management FlashCards sobre Flashcards OM: Process Thinking, criado por Fredrik Josefsson em 18-12-2017.
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- Fredrik Josefsson
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