What is a fixed position layout? What products is it used to make?
the product does not move throughout production, the resources and manpower do.
eg. ships, buildings and trains
What is process layout? what are some examples?
machines are grouped into departments or stations according to the operations that they perform.
eg. pressing department, lathes department
What is product layout? what are some examples?
machines are grouped according to the product manufacturing sequence.
called manufacturing lines
ex. used for high volume component parts
What are cellular layouts? what are some examples?
- different modules are produced in different lines and assembled as subsets
- cell has responsibility for producing a family of like parts or single product
- all necessary manpower and equipment are contained in cell
ex. automotive
What are the advantages of cellular layouts?
- can be used for a great variety of products
- increases efficiency
- used for small lots sizes
- lead time is shorter
- best for products with a short life cycle
- caters to a higher product mix
What is a task?
a set of necessary steps that the work gets decomposed into
-is considered the smallest assignable unit to a cell
What is a workstation?
the logical organization of specific manufacturing or assembly equipment to perform tasks
-the number should be as small as possible
What are some disadvantages of cellular designs?
- more movement of materials
- more works needed for movement of materials
What is takt-time? what is the calculation for takt time?
is the time between starting to work on one unit and starting the next.
What is cycle time? How is it calculated?
is the normal time to complete an operation on a product in each workstation
Calculation:
sum of the task times that a product requires at each station
Preferably, should cycle time be more the takt-time? why?
Cycle time should be less then or equal to takt time. Because if it is not, orders will get behind and you will have late orders, unhappy customers and more expediting of products.
What is idle time? how is it calculated?
Paid time during which an employee, or machine is not doing anything productive.
What is a precedence diagram?
It is a diagram that shows the order of the parts being manufactured
What is group technology?
is a tool used in engineering and production departments to identify similar products.
What is a time study?
the methods used to determine the standard time for an operation
- the time qualified worker needs to carry out a specific task , working in a normal rhythm during a work day
What is leveling production?
it is a prerequisite required for a cellular layout transformation
-corresponds to the production and scheduling strategy
What are advantages to multifunctional workers?
- reduction in work-related accidents
- improves the relationships among labours
- facilitates knowledge sharing
- uncover expert workers in each task
What are the prerequisites for cell disigning?
- mulitfunctional workers
- determine the reuired space for the cells
- invest in new machinery
- improve the set-up time of dies
- look for simple methods for production automation
- choose new production planning and control systems so the future planning or control of the line is not required
What is the main goal of line-balancing?
- to assign tasks to workstations so that the minimum number of workstations can be achieved
- in each workstation the cycle time is less then takt-time
- the idle time in minimal
What are the steps in line balancing?
- define the tasks and their times
- specify the precedence relationships
- determine the takt-time
- calculate the minimum number of workstations
- choose a task assignment rule
- assign tasks
- determine the total idle time
- analyze, if not suitable choose another rule
When is a task eligible to be assigned?
it it has not yet been assigned and all that precede it have been
What are the heuristics?
-total number of following tasks- choose the task with the largest total number of following tasks
if more then two pick the one with the longest time
-individual durations -which has the longest time
if two pick the one that has the longest total number of following tasks
