page_72 - .KL to.JK(see Figure 4.8 Both maufacturing and...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
< previous page page_72 next page > Page 72 Level K is a level calculated at the present time. Level J is a level calculated one time interval earlier. DT (delta time) is the length of the time interval between J and K . For our stock level equation we therefore have SL.K = SL.J + DT(M.JK - D.JK) (4.4) So the stock level at any time (say K ) is equal to the level one time interval earlier (therefore J ), plus the difference between manufacturing ( M ) input during that time interval ( JK ) and the delivery ( D ) output over that time interval ( JK ). Rates enable progress to be made in steps determined by DT . At time K the state of the levels (at time period
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
one) will determine the rate for the next time period, that is KL (at time period two). In the next time step, what was L (the future) is now K . Therefore, the timescript representing that rate changes from
Background image of page 2
Background image of page 3
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: .KL to .JK (see Figure 4.8). Both maufacturing and delivery rates are variable. Let us assume that we have control over the manufacturing rate but that demand is outside our control (we are attributing no importance to marketing and sales). According to our diagram in Figure 4.5, manufacturing rate is influenced by stock level, so if stock level falls below a desired level, manufacturing rate will rise. We will assume that an indicator on demand ( DI ) can be derived from stock level and desired stock level ( DSL ) which is a constant DI.K = DSL - SL.K (4.5) Manufacturing rate can therefore be expressed in the following way Figure 4.8 How time notations are worked out for system dynamics models < previous page page_72 next page >...
View Full Document

Page1 / 3

page_72 - .KL to.JK(see Figure 4.8 Both maufacturing and...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online