,Fast-reading version, 7 chapters on 18 pages
Chapter 1: Supply chain management and logistics
Cycle time: equals the total time required to complete the total process from
raw materials to the delivery of the finished product to the customer
Logistics: part of the supply chain process that plans, implements, and
controls the efficient, effective flow and storage of goods, service and
related information from the point of origin to the point of consumption
in order to meet customer’s requirements
- Planning of transport
- Planning of production
- Selecting third logistics party
- Estimation of number of returned goods
- Estimation of number of goods to be produced
- Estimation of inventory of products necessary
Objective: expression that maximises or minimises some goal
- Maximise quantity to be produced
- Maximise profit
- Minimise costs
- Minimise cycle times
Constraints: restrictions that limit the degree to which an manager can pursue an
objective
- Total waiting time < 1 hour
- Total inventory < 100 units
- Occupancy degree > 0.90
Efficiency: do the job right at;
- Minimal investments and costs
- And utilisation rates and throughput times
Effectiveness: do the job right;
- Right products
- Right time
- Right customers
- Right quality
- Right quantity
Single factor productivity:
Input factor: labour, capital, management
Multi factor productivity:
, Chapter 2: Process analysis
If a production/service time follows a normal distribution
Normal(µ,σ) then
deviatio
Standar
- The mean equals µ
- The standard deviation equals σ
d
- The probability that a production
time falls between µ-σ and µ+σ is
68%
- The probability that a production
time falls between µ-2σ and µ+2σ
is 95%
Alternatives to find an estimate for a certain
performance measure (such as production
speed, or waiting time of customers)
- Educated guess (deterministic
performance estimation)
- Experimentation with the real system
- Experimentation with physical models
(on scale or full-size)
- Experimentation (or calculating) with Mean
analytical models (mathematical,
statistical, etc.)
- Experimentation with simulation models
Interarrival time: time between two subsequent arrivals of products at their
entrance in the process Arrival rate: number of products that arrive per time
unit (e.g. number of products that arrive per hour)
Throughput time: time that passes between the moment at which the
customer/product enters the system and the moment at which the
customer/product is ready
- Deterministic throughput times can be estimated by adding up the
expected processing times of the different processes
Step to solve a question with multiple paths
1. Estimate deterministic throughput time for one of the paths
2. Multiply resulting deterministic throughput time with probability that
the path will be followed
3. Repeat 1 and 2 until all paths are handled
4. Total deterministic throughput time is sum of results of step 2 for all paths
Design capacity: theoretical maximum output of a system or process in a given period
Effective capacity: capacity that can be expected given the product mix,
methods of scheduling, maintenance and standards of quality
Is design capacity sufficient to handle the expected number of products
that arrive at the various processes?
1. Calculate design capacity of each process
2. Calculate the expected number of products arriving at that process
(use percentages in systems with multiple paths)
3. Compare answers step 1 and 2
Chapter 1: Supply chain management and logistics
Cycle time: equals the total time required to complete the total process from
raw materials to the delivery of the finished product to the customer
Logistics: part of the supply chain process that plans, implements, and
controls the efficient, effective flow and storage of goods, service and
related information from the point of origin to the point of consumption
in order to meet customer’s requirements
- Planning of transport
- Planning of production
- Selecting third logistics party
- Estimation of number of returned goods
- Estimation of number of goods to be produced
- Estimation of inventory of products necessary
Objective: expression that maximises or minimises some goal
- Maximise quantity to be produced
- Maximise profit
- Minimise costs
- Minimise cycle times
Constraints: restrictions that limit the degree to which an manager can pursue an
objective
- Total waiting time < 1 hour
- Total inventory < 100 units
- Occupancy degree > 0.90
Efficiency: do the job right at;
- Minimal investments and costs
- And utilisation rates and throughput times
Effectiveness: do the job right;
- Right products
- Right time
- Right customers
- Right quality
- Right quantity
Single factor productivity:
Input factor: labour, capital, management
Multi factor productivity:
, Chapter 2: Process analysis
If a production/service time follows a normal distribution
Normal(µ,σ) then
deviatio
Standar
- The mean equals µ
- The standard deviation equals σ
d
- The probability that a production
time falls between µ-σ and µ+σ is
68%
- The probability that a production
time falls between µ-2σ and µ+2σ
is 95%
Alternatives to find an estimate for a certain
performance measure (such as production
speed, or waiting time of customers)
- Educated guess (deterministic
performance estimation)
- Experimentation with the real system
- Experimentation with physical models
(on scale or full-size)
- Experimentation (or calculating) with Mean
analytical models (mathematical,
statistical, etc.)
- Experimentation with simulation models
Interarrival time: time between two subsequent arrivals of products at their
entrance in the process Arrival rate: number of products that arrive per time
unit (e.g. number of products that arrive per hour)
Throughput time: time that passes between the moment at which the
customer/product enters the system and the moment at which the
customer/product is ready
- Deterministic throughput times can be estimated by adding up the
expected processing times of the different processes
Step to solve a question with multiple paths
1. Estimate deterministic throughput time for one of the paths
2. Multiply resulting deterministic throughput time with probability that
the path will be followed
3. Repeat 1 and 2 until all paths are handled
4. Total deterministic throughput time is sum of results of step 2 for all paths
Design capacity: theoretical maximum output of a system or process in a given period
Effective capacity: capacity that can be expected given the product mix,
methods of scheduling, maintenance and standards of quality
Is design capacity sufficient to handle the expected number of products
that arrive at the various processes?
1. Calculate design capacity of each process
2. Calculate the expected number of products arriving at that process
(use percentages in systems with multiple paths)
3. Compare answers step 1 and 2
