Design of Production Facilities Flashcards
How do you approach for functional layouts?
-The plant layout problem, where the position of the different departments relative to one another has to be determined.
What needs to be considered in plant layout problems?
- Buildings and space
- Material handling
- Utilities, communications, facilities
- Affinity
What is an affinity ranking?
- Used to make a visual map of the layout of the plant with respect to the shared need e.g water, cleanliness, power, material, handling or staff
What is the affinity ranking process?
1) Collect information on material flows between areas and the cost of moving per unit distance.
2) Draw a schematic layout, indicating traffic levels or costs and adjust this so that the highest cost routes are as short as possible
3) Try and error, asses and look for overall cost of traffic.
4) Once minimised craw floor plan.
What is batch production?
- Group of identical products are produced simultaneously.
What is a manufacturing cell?
- Sets of machines that are grouped by the products or parts that they produce.
How is part family identification useful for batch production?
- Could potentially be processed by a manufacturing cell.
- Sometimes this is obvious from design, at other times more complex.
What is rank order clustering? (ROC)
- Rank Order Clustering, involves organising columns and rows in the order of decreasing binary weights.
What is the method for rank order clustering?
1) create a table indicating which parts are processed by which machines.
2) Read 0’s and 1’s across a row as a binary number.
3) Re-order the rows high to low in terms of their binary number.
4) Then “read” the 0’s and 1’s down a column as a binary number.
5) Re-order the columns in terms of their binary number.
6) Repeat the procedure until there’s no change in the final answer.
How do you identify product families for rank order clustering?
- To assess production volumes and see if a dedicated cell is justified.
- Assess the arrangement of machines in a cell, possibly using same techniques as for functional layout.
- (Neat answers are uncommon).
How do you approach a question that is “not so neat”?
- Product redesign for manufacture.
- Tolerating some machine under-utilisation.
- Requiting some components to flow through more than one cell.
- Having mixed functional and cellular layout.
What are “Flowlines” defined as?
- ## Arrives > processed sequentially at a series n > then exits.[1]===[2]==[3]===[4]====
What are workstations?
- Can be area of factory, a desk or bench, or a specialised workstation, with all tools/parts available.
- Can be automated or manually operated.
(track can be overhead crane/conveyer belt, roller table/robot)
What is the sequence of events for flowlines?
1) Parts move from station to station and part and/ or operators are put in position.
2) This takes an amount of time called the repositioning time, Tr
3) At each workstation manufacturing or assembly operations are performed
4) This takes an amount of time called service time Ts and alternates depending on station Ts (i=n)
5) Once all workstations have completed their operations the cycle repeats.
What is Tr, Ts and Ts(i)?
- Tr is the repositioning time.
- Ts is the service time.
- Ts(i) is the service time at a specific station i= 1, 2, 3…..
