F3 Planning and controll

Question 1

Vad är operations

Answer 1

• The scope of operations is to match supply with
  demand, while aligning with companies’ vision /
  strategies.
• To accomplish this scope by establishing stable
  processes and measurement systems

Question 2

Vad gör en planerare (operations controll) på air france

Answer 2

‒ Optimal flight routes
‒ Anticipate problems, e.g. pilots strikes, weather changes etc.
‒ Improve margins, i.e. maximize revenues and minimize costs, e.g. fuel consumption.
‒ All planning documents need to be ready for the flight crew, who will receive and check them before departure.

• Important elements in the planning:
  ‒ Frequency  for each airport what routes and frequency are needed.
  ‒ Fleet assignment  how should flights be scheduled.
  ‒ Banks  i.e. arranging optimal transfer.
  ‒ Block time  time from the moment a plane leaves a departure gate at an airport and arriving to its gate in the arrival airport.
  ‒ Planned maintenance  allow for necssary inspection and maintenance.
  ‒ Crew planning  schedule pilot and cabin crew. Maximize working hours, while reducing costs (e.g. allowances).
  ‒ Gate plotting  schedule access to gates.
  ‒ Recovery  account for deviations and ensure some tolerance is built-in the system.

Question 3

Planning och kontroll över tidsperspektiv

Answer 3

Long-term planning and control
Aggregerade efterfrågeprognoser
Bestämmer resuser i aggregerad form
Mål sätts i financiell form

Medium-term planning and control
Delvis avaggregerad prognos
Bestämmer resurser och situationsfaktorer
Mål sätts i både financiella och operationella termer

Short-term planning and control¨
Fullständigt avaggregerad prognos
Gör ingripanden av resurser för att korrigera avvikelser från planen

Question 4

Volume-variaty påverkan på plannering och kontroll

Answer 4

Consider job shops vs oil refineries, what is the
importance of planning and control for those two
process types?
* Architect Studio vs Electricity Utility.
* A Studio has normally a high variety/highly
customised projects. Can they produce in advance? Do they need planning?
* Long-term, no planning is needed. Opposite for
short-term planning.
* Electricity utility  volumes are high, production is continuous, and variety non-existent. Facilities needed to produce electricity requires huge investments, increasing the need for long-term

Avvikelser

Question 5

Sales and operations

Answer 5

Olika funktioner involverade i operations har vanligtvis olika mål
S&op integrerar kort och långsiktig planering och integrerar planeringen av nyckelfunktioner
Det är en aggregerad process som inte kollar på detaljer
Kan heta andra saker

Question 6

Säker vs osäker efterfrågan

Answer 6

Bildäck
Nya bilar vs privatkunder vill ha nya däck

Question 7

P-D ratio

Answer 7

Make to Order  a service or a product is not produced
until an order is received.
Make to Stock  anticipate demand. Manufacture in
advance

P:D ratio is low, much uncertainty is removed
(except from the production cycle).
* P:D ratio is high, uncertainty is higher and
operations and planning activities are more
speculative.

Question 8

Vilka aktiviteter finns det i planning and controll

Answer 8

Loading
Sequencing
Scheduling
Monitoring and controll

Question 9

Vad innebär loading

Answer 9

Hur mycket

Question 10

Vad innebär sequencing

Answer 10

I vilken ordning ska saker göras

Question 11

Vad innebär Scheduling

Answer 11

När ska saker göras

Question 12

Vad innebär monitoring and controll

Answer 12

Går aktiviterna enligt planen

• Once loading, sequencing and scheduling have
  been performed, each part of the operation needs
  to be monitored and controlled.
• Necessary to do to ensure that the planned
  activities are indeed happening.
• If not, any deviations of plans can be rectified.

Question 13

Vilka olika typer av loading och när ska man använda de

Answer 13

• Finite Loading:
• Work over/above capacity is not allowed.
• Load can be limited using appointment
  systems
• It can be specified by safety regulations.
• Cost of limiting load is low
• Infinite Loading:
• Loading is not limited but the system tries
  to cope with it.
• Capacity can be flexible and adapted to
  different arrival rates.
• The cost of limiting the loading is high.

Question 14

Exempel på saker som konsumerar up time för maskiner

Answer 14

Planerade perioder utan jobb
Oplanerade perioder utan jobb
Breakdowns
Långsam körning
Kvalitetsförluster
Omställning mellan körning

Maximal tillgänglig tid

Värdefull operationstid alltind < 168h/w

Question 15

Olika former av sequencing

Answer 15

‒ Physical constraints
‒ Customer priority
‒ Due date
‒ Last in First Out (LIFO)
‒ First In First Out (FIFO)
‒ Longest Operation Time (LOT)
‒ Shortest Operation Time (SOT)

Question 16

Hur utvärdera olika sequencing

Answer 16

‒ Meeting due date promised to customers or days of lateness.
‒ Minimize flow time (time spent in process).
‒ Minimize work in progress inventory.
‒ Minimize idle-time.

Question 17

Olila typer av scheduling

Answer 17

Forward scheduling
Backword scheduling

Question 18

Vad innebär theory of constraints

Answer 18

Any operating system is always limited by a small number of constraints. i.e. there is always at least one process or resource which limits the whole operating system.

These constraints, e.g. the most loaded resouces, set the pace at which the system works. These are also known as bottlenecks.

Bottlenecks determine utilization rates of processes/stations before and after the bottleneck.

Any improvement done to the system should start from its bottlenecks!

Question 19

Vad innebär drum buffer rope

Answer 19

• A bottleneck is also called ”drum” because it
  sets the beat of the following activities. Starvation appears in the following activities.
• It is important bottlenecks are always
  operating and to ensure this, a ”buffer”
  inventory before the bottlenecks is needed or
  activities in front will have to wait for the
  bottleneck.
• ”Rope”: communication / information sharing
  is needed between the bottleneck and
  preceding activities, to ensure that these do
  not overproduce and flood the buffer or line

Question 20

Vad innebär capaciry managment

Answer 20

‒ Understanding the nature of demand
and supply and thereby reduce
mismatches,
‒ Reconcile demand, customer
satisfaction and resource efficiency

Question 21

Långsiktig capacity managment på enterprice nivå

Answer 21

Strategic capacity planning
* Horizon time of years and months
Concerns:
* Buildings, facilities and process
technology
* Long-term supply arrangements

ger constraints till undre nivåer och får feedback från de

Question 22

Medium-term capacity management

Answer 22

• Horizon time of quarters, months
  and weeks
  Concerns:
• Aggregate number of people
• Degree of subcontracted
  resources

Constraints får ovanifrån och ger ner
Feedback: Får under och ger upp

Question 23

Short-term capacity management

Answer 23

• Horizon time of weeks, days, hours
  Concerns:
• Loading activities on individual
  processes and staff

Constraints får ovanifrån
Feedback: ger upp

Question 24

Vilka prestationsmål har man i capacitymanangment

Answer 24

• Costs  costs appear if capacity is over- or under- utilized.
• Revenues  these are also affected when capacity does not match demand, as a consequence of changed
  profits and costs.
• Working Capital  an increment of manufacturing capacity may lead to increase of finished product inventory.
• Quality  fluctuations in capacity, e.g. hiring temporary workers, may lead to defects or similar quality concerns.
• Speed  responsiveness can be affected. If capacity increases queues are avoided, reducing waiting times. At
  the same time, building up inventory improves responsiveness.
• Dependability  when demand and supply matches perfectly, we will not be able to respond to supply
  disruptions.
• Flexibility  if demand and capacity are in balance, the operation will not be able to respond to unexpected
  changes of demand.

Question 25

Capacity managment framework

Answer 25

SUPPLY SIDE Measure capacity to deliver: products and services Consider impacts of mix, time frame and specification Manage the supply side: Determine base capacity Select ‘level’ or ‘chase’ capacity plans DEMAND SIDE Measure demand for products and services: Select qualitative and/or quantitative methods to support forecasting Manage the demand side: Demand management Yield management Understand the consequences of different capacity management decisions: Use predictable versus unpredictable demand assessment, cumulative representations, queuing principles, and a longitudinal perspective to support decision making

Question 26

Hur kan man mäta kapacitet

Answer 26

‒ Flow time / process time into Flow rate / process rate. ‒ Utilization rate ‒ Service level (value adding persp.)

Question 27

Skillnaden mellan input och output mått

Answer 27

* Activity Mix * Time dependance Hospital Beds available Number of patients treated per week Air-conditioner plant Machine hours available Number of units per week Theatre Number of seats Number of customers entertained per week University Number of students Students graduated per year Electricity company Generator size Megawatts of electricity generated Retail store Sales floor area Number of items sold per day Airline Number of seats available Number of passengers per week Brewery Volume of fermentation tanks Litres per week

Question 28

Skilladen mellan design kapacitet, effektiv kapacitet och verkligt output

Answer 28

Design capacity = the theoretical capacity of an operation based on the original design. * Effective capacity = the capacity of an operation, excluding planned losses. * Actual output = capacity of an operation, excluding planned and unplanned losses (e.g. sickness, employees mobility, machines breakdowns, demand changes, etc.)

Question 29

Formel för utilization

Answer 29

Utilization = Verkligt output/ Designkapacitet

Question 30

Formel för effektivitet

Answer 30

Effektivitet = Verkligt output / Effektiv kapacitet

Question 31

Formel för overall equipment effectivness

Answer 31

* The capacity reduction, due to predictable and unpredictable losses, results into ”capacity leakage” * A popular method to assess this leakage is the OEE (Overall Equipment Effectiveness) * OEE = a x p x q, where ‒ a = availability of a process ‒ p = performance/speed of a process ‒ q = quality of products/services created

Question 32

Olika planer för supply managment

Answer 32

Level capacity plan Chase capacity plan

Question 33

Capacity management strategies, based on short- versus long-term volumes

Question 34

Olika planer för demand managment

Answer 34

‒ Price differentials: adjust prices depending on demand (high/low season) ‒ Scheduling promotions: encourage demand during low season. ‒ Constraining customer access: allow access only at particular times of day/week/month ‒ Service differentials: degrade service during high season, improve during low demand periods. ‒ Create alternative products / services: deviate demand on available products / servcices. ‒ Yield management: study past data to understand underor overbooking risks, change prices based on season or capacity.

Question 35

Kapacitetsstrategier

Answer 35

Kapacitet kan leda eller lagga efter efterfrågan

Question 36

Hur upplever kunder köer

Answer 36

1 Unoccupied time feels longer than occupied time. 2 Pre-process waits feel longer than in-process waits. 3 Anxiety makes the wait seem longer. 4 Uncertain waits feel longer than known, finite waits. 5 Unexplained waits feel longer than explained waits. 6 Unfair waits feel longer than equitable waits. 7 The more valuable the service, the longer customer will ‘happily’ wait. 8 Solo waiting feels longer than group waiting. 9 Uncomfortable waits feel longer than comfortable waits. 10 New or infrequent users feel they wait longer than frequent users.

Question 37

Vad är planning and controll

Answer 37

 Planning and control is the reconciliation of the potential of the operation to supply products and services, and the demands of its customers on the operation. It is the set of day-to-day activities that run the operation on an ongoing basis.  A plan is a formalisation of what is intended to happen at some time in the future. Control is the process of coping with changes to the plan and the operation to which it relates. Although planning and control are theoretically separable, they are usually treated together.  The balance between planning and control changes over time. Planning dominates in the long term and is usually done on an aggregated basis. At the other extreme, in the short term, control usually operates within the resource constraints of the operation but makes interventions into the operation to cope with short-term changes in circumstances.

Question 38

Vad är capacity managment

Answer 38

Capacity management is the activity of understanding the nature of demand for services and products, and effectively planning and controlling capacity.  Capacity decisions are taken across multiple time horizons and each level of capacity decision is made within the constraints of a higher level. In the other direction, short-term decisions provide important feedback for longer-term planning.

Question 39

Vad ska en bra demand forecast göra

Answer 39

Good demand forecasts should: (1) be as accurate as possible; (2) give a clear indication of relative uncertainty; (3) be expressed in terms that are useful for capacity management (e.g. units per hour, operatives per month, etc.).

Question 40

Exempel på kvalitativa demand forecast metoder

Answer 40

panel, delphi, scenario plannering

Question 41

Vad är capacity

Answer 41

 The capacity of an operation is the maximum level of value-added activity over a period of time that the process can achieve under normal operating conditions.  Capacity can be measured by the availability of its input resources or by the output that is created.

Question 42

Vad är demandmanagment

Answer 42

 ‘Demand management’ involves changing the pattern of demand to bring it closer to available capacity. This is achieved by either stimulating off-peak demand or constraining peak demand.  A number of methods are used to manage demand, including price differentials, scheduling promotion, constraining customer access, service differentials and creating alternative products or services.  Yield management is a common method of coping with mismatches when outputs cannot be stored.

Question 43

Vad är capacity planning

Answer 43

 Capacity planning often involves setting a base level of capacity and then planning capacity fluctuations around it. The level at which base capacity is set depends on three main factors: the relative importance of the operation’s performance objectives, the perishability of the operation’s outputs, and the degree of variability in demand or supply.  ‘Level capacity’ plans involve no change in capacity and require that the operation absorb demand– capacity mismatches, usually through under- or over-utilisation of its resources, or the use of inventory.  ‘Chase’ (demand) plans involve the changing of capacity to track demand as closely as possible. Methods include overtime, annualised hours, staff scheduling, varying workforce size, using part-time staff, increasing skills flexibility, subcontracting, zero hours contracting and changing the output rate.

Question 44

Vilka faktorer ska man tänka på när man sätter Base capacity

Answer 44

Den relativa vikten av olika prestationsmål Graden av "perishibility" av outputs Graden av variability i demand eller supply