SMS – What is it… ?
- A decision support tool for setting inventory levels for critical, slow moving and high cost parts
- Forecasts inventory levels for in-house repair, sub-contract repair and new purchases based on the required reliability, cost and equipment availability
- Aligns spare parts replacement decisions with the Equipment Reliability process and the current business situation (risk and cost)
- Combines science and economics to set inventory levels according to operations and performance needs, not just budgets
- Facilitates placement of final orders for discontinued parts
The SMS Benefits
- Improved decision making, reduced cost of spares
- Integrates risk and cost calculations
- Forecasts timing of replacements for current spares
- Sets the Spares levels required to meet multiple replacement conditions and % reliability requirements:Accommodates variable failure intervals, variable lead times, variable repair times
- instant reliability (spare is available when called for)
- interval reliability (spare is available during the period being planned)
- cost minimization
- availability of the process or production unit
- given a stock size, the availability during the period being planned
- Provides cost calculations for repairable and non-repairable spares
- Complementary to RCM
- Easy to use data entry screens requires little training
- Easy to read graphical output shows results at a glance
Input Data
- The required planning period
- The type of calculation required – instant or interval reliability, availability or cost minimization
- The % level of reliability required
- The cost of the spares – new and repaired – regular cost, emergency cost, holding cost, cost of capital, future value of unused spares
- Failure rates for the spares
- Lead times for the new and repaired parts
Outputs
- Risk and cost calculations for Repairable Spares
- Risk and cost calculations for Non-Repairable Spares
- Minimum level of Spares requirements for Interval reliability at user determined levels from 50% to 99.99%
- Minimum level of Spares requirements for Instant reliability at user determined levels from 50% to 99.99%
- Availability calculations at given levels of Spares
Case Study
Randomly failing motors
- Plant Availability at 95%: = 0 spares
- Plant Availability at 99%: = 2 spares
- Instant reliability (always one when wanted): 95% reliability = 4 spares
- Cost minimization: = 6 spares
- Interval reliability (never run out): 95% reliability = 7 spares
Target Industries
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Any industry where Spare Parts and Replacement costs are a significant part of operations
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Any heavy industry such as mines, steel, metals processing, chemicals, oil and gas petrochemical, pulp and paper
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Discrete manufacturing facilities – automotive, electrical, components, furniture, tires, plastics etc
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Process manufacturing – pharmaceuticals, food and beverages
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Municipal, state and federal departments, military, customs, airports, container ports
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Power utilities, telecom, gas, electrical, water distribution companies