week 6: process selection Flashcards
name some selection drivers
- product quantity
- tooling cost
- labour intensity
- maintenance
- material cost and availability
- component form and dimensions
- surface finish needs
- process to component variability
- component recycling
- equipment cost
- processing cost
- process supervision
- energy consumption
- material to process compatibility
- tolerance reqs
- bulk treatment
- process waste
what are the three types of process
- transformative (mass of part remains the same)
- subtractive (mass reduces)
- additive (mass increaeses)
what is direct and indirect cost
Direct - directly on making product, scales linearly with quantity and includes material labour
Indirect - cannot be directly attributed to product
- manufacturing (rent, heat, power, staff, cleaning, transport etc.)
- business (research, design, development, sales, marketing, finance, legal, directorate)
time categorization of cost
- capital cost or fixed cost (setting up system)
- yearly running cost (total expenses in a year)
deprecatiation
the capital cost divided by the number of years that the capital purchase remains in use
cost estimation: bottom up approaches
Activity based costing:
- relies on assignment of overheads based on activities that take place within the manufacturing system
Volume based costing:
- assignment of overheads to products based solely on machining time or labour
cost estimation: top down approaches
- costing process is abstracted and cost determined without considering every detail of manufacturing process
- parametric models for costing where a mathematical model used in conjunction with values in model for product design
- stats models
- baseline costing ( cost from existing product)
process capability
measure if acceptability of the variation of the product
simplest measure is the ratio of the specification range to the natural variation
