Good Stuff Happens in 1:1 Meetings: Why you need them and how to do them well
Dry and Buy decision for kiln scheduling
1. Dry-or-buy decision support for dry
kiln scheduling in furniture production
ARMAN R. YAGHUBIAN, THOM J. HODGSON & JEFFREY A. JOINES
Himanshu Bhokarikar | Ankit Ranjan
Biswa Ranjan Barik | Vardhan Reddy
Project 15
OHM Term Project
3. FURNITURE
MAKING
PROCESS
Shaping,
Finishing,
Polishing etc.
GREEN LUMBER
X
DRIED LUMBER
Cost
Dried Lumber procuring methods
Buying Dried Lumber from
open market
Buying Green Lumber and
drying using inhouse kilns
Background
Understanding furniture production:
Green lumber Vs dry lumber - root cause for dry-buy decision
Raw Wood Green Lumber Dried Lumber
Dimensional stability
Biological degradation
Strength
Nail holding ability
Low
High
V. Low
Low
Low
V. High
Low
High
High
High
Significantly more expensive Comparatively cheaper
Assumed unlimited supply
Supply is limited by the
capacity of in-house kilns
Risk
Assessment
Introduction
Methodology
Analysis
Mitigation
Introduction
Conclusion
Modelling
Formulation
4. Possible
Solutions
1 2
3
Iterative "What-If" Cost Analysis
X
Trial-and-error, suboptimal for
large problem
Mathematical programming, cost
minimization (IP)
NP-completeness, computational
complexity
Three-phase heuristic
local search
Faster computation, not always
optimal
Background
Solution Approaches and Constraints:
Iterative, LP, Heuristics
Risk
Assessment
Introduction
Methodology
Analysis
Mitigation
Introduction
Conclusion
Modelling
Formulation
6. OBJECTIVE
FUNCTION
X
Decision
Variables
Amount of demand j
outsourced
No. of jobs assigned to
kiln k of demand j
Parameters
Per Sq. Foot cost
of dried lumber
Cost of drying
demand j in kiln k
Demand j
(in board feet)
Per Sq. Foot cost
of green lumber
Risk
Assessment
Introduction
Methodology
Analysis
Mitigation
Formulation
Understanding furniture production:
Formulating trade-off between buying Vs drying lumber
Cost of Buying
Dried Lumber
Total cost of
Drying Green Lumber
Cost of Buying
Green Lumber
Introduction
Conclusion
Modelling
Formulation
7. 1
2
3
The processing time + starting time of a job
Should be lesser than the Due Date
X
Formulation
Understanding furniture production:
Constraints
In-house dried lumber (in sq. foot) + Outsourced
dried lumber would be Greater than Total Demand
Both the decision variables should
be Positive Integers
Risk
Assessment
Introduction
Methodology
Analysis
Mitigation
Introduction
Conclusion
Modelling
Formulation