Faculty of Organizational Sciences,
University of Belgrade, Serbia
SPREADSHEETS IN EDUCATION OF
LOGISTICS MANAGERS AT FACULTY OF
ORGANIZATIONAL SCIENCES: AN
EXAMPLE OF INVENTORY DYNAMICS
SIMULATION
L. Djordjevic, D. Vasiljevic
djordjevic.lena@fon.bg.ac.rs, vasiljevic.dragan@fon.bg.ac.rs
Agenda
› Spreadsheets
› Spreadsheet applications in education
› Spreadsheets in logistics management education
› Spreadsheet model of inventory control
› Logistics problems modeled as discrete
controlled object in spreadsheet
› General remarks and future directions
Spreadsheets
› For tracking information, business processes and flows in
the organization
› For business modeling, analysis and decision support
› As computing and teaching tool
› For teaching-learning process improvement
Spreadsheets for…
› Numerical calculations
› Information visualization
› Reports generating
› User interface definition
› Complex models defining
› Automation of activities (VBA)
Spreadsheets application in education
› Finance and accounting
› Engineering studies
› Business management
› Operations research
› Logistics education
›…
Spreadsheets in logistics management
education
› Integrated spreadsheet models
–
–
–
–
–
logistics strategies
flow planning
inventory control
allocation and aggregate planning
network design and planning
› Visual impact to the logistics problems analysis
› Required flexibility
› Modeling approach combined with case analysis
Spreadsheet model of inventory control
› Discrete controlled object concept for logistics problems
modeling
› Clear separation between:
– a discrete object (low of behavior, control domain)
– a performance criterion
– method used to find an optimal solution
Logistics problem modeled as discrete
controlled object
Control domain
Law of dynamics
Performance criterion
cost = ordering cost + holding cost + purchase cost
1, if Yt1  0
1
(min) J   [Cs  

Ch

dav
(
t
)

Cu

Y
]

t
1
t 1
0, if Yt  0
T
Logistics problems modeled as discrete
controlled object in spreadsheet
Spreadsheet model of inventory control in the case of fixed order replenishment cycle in the finite time
horizon
Logistics problems modeled as discrete
controlled object in spreadsheet
Interpretation of mathematical model in spreadsheet
Logistics problems modeled as discrete
controlled object in spreadsheet
› Data Table function
› Dynamic range that summarizes formula cells for varying
input cells
– Find optimal number of replenishments
– Minimal value of performance criterion J
– Check less than T values for the control variable u1
› Tool for students to better understand dynamics of the
inventory on the day by day basis
Approach application
› Faculty of Organizational Sciences, University of Belgrade,
Serbia
› Students of the third and fourth years of undergraduate
studies
› Benefits
–
–
–
–
–
–
focus on the individual parts of the problem
inventories behavior
relationship between input and output flows of inventories
admissible solutions space defining
performance criterion
different methods of optimal solution finding
General remarks and future directions
› Students are allowed to
–
–
–
–
understand the problem
develop mathematical model
translate it to spreadsheet model
run simulation
› Future directions
– Integration of spreadsheet models and heuristic methods
– Developing of logistics problems models examples
– Library of useful templates for students
Thank you for your attention!