Forecasting 2 Flashcards
Vad är trend projection adjusted for seasonal influence?
Forecasting with trend and seasonal components is a method used when a time series has both mentioned components.
Steps för forecasting with trend and seasonal components
- Calculate the centered moving averages (CMAs).
- Center the CMAs on integer-valued periods.
- Determine the seasonal and irregular factors (StIt ).
- Determine the average seasonal factors.
- Scale the seasonal factors (St ).
- Determine the deseasonalized data.
- Determine a trend line of the deseasonalized data.
- Determine the deseasonalized predictions.
- Take into account the seasonality.
How is regression analysis used in other ways?
Other applications of using regression analysis is using it to analyze relationship between any to variables.
Examples how regression analysis is used:
Estimating cost function
Estimating revenue function
Estimating demand function
Formulas for cost, revenue and demand function
C(X) = f+vX
R(X) = pX
X(p) = a-bp
Vad står C(X), f och v för?
C(X) = Totala kostnader vid X antal produktion
f = fasta kostnader
v = rörliga kostnader per enhet
Vad står X(P), a, b och p för?
X(p) = efterfrågan antal sålda enheter vid pris p
a = efterfrågan om priset är 0 (teoretiskt maximal efterfrågan)
b = priselastisitet, hur mkt efterfrågan minskar när priset ökar
p = pris per enhet
What is profit maximizing pricing?
Profit maximizing pricing is a method to maximize profit. It is made by finding the quantity, X*, that maximizes profits.
What functions must we know to use profit maximizing pricing?
Cost function and Demand function
When do we maximize profit?
When MR = MC
What defines correlation coefficient? r
-1 till 1
Visar i vilken mån dependent and independent variable är linearly related
r > 0 = positive slope
r < 0 = negative slope
r = 0 = no linear relationship
r = +1 = positive slope where all values on a straight line
r = -1 = negative slope where all values lay on a straight line
What defines determination coefficient? r2
0 till 1
Visar hur stor del av the variation i the independet variable is explained by the variation i the independent variable
r2 = 1 = perfectly correlated
r2 = 0 = no correlation
3 qualitative approaches to forecasting
Delphi approach, Scenario writing, Subjective or Interactive Approaches
Describe Delphi approach
Consists of a panel of experts, each of whom is physically separated from the others and is anonymous.
The group is asked to respond to a sequential series of questionnaires and send it in.
After each questionnaire, the responses are tabulated (i tabellform) and the information + opinions of the group are made known to the members.
They can revidera their answers based on the groups opinions and that continuous until consensus (samstämmighet) is achieved.
Describes scenario writing
Consists of developing a conceptual scenario of the future based on a well defined set of assumptions.
After several different scenarios have been developed, the decision maker determines which is most likely to occur in the future and makes decisions accordingly.
Describe subjective or Interactive Approaches
Are often used by committees or panels seeking to develop new ideas, alternativt att lösa komplexa problem.
Oftast är brain storming sessions involverade och its important that any ideas or opinions are permitted to be presented without the matter of if its relevancy and without fear of criticism.
