Periodic Payment License

DECs Periodic Payment License (PPL) was a kind of software leasing system, which was introduced about 1987.

Instead of buying a relatively expensive traditional Paid-Up license (with unlimited validity), you could start with a one-time Initial License Charge and monthly Periodic Payment License (PPL) fees.

Which of the two options leads to lower overall costs depends on the period of use.

Let's have a look at an example:

Q2001-1P VAX 8550 VMS INITIAL LICENSE FEE                       1  x 3,150 =  3,150 
Q2001-JP VAX 8550 VMS MONTHLY PERIODIC PAYMENT LICENSE FEE      41 x 1,134 = 46,494
                                                                     Total = 49,644 

Q2001-UZ VMS PAID-UP LICENSE                                                 49,875

The break-even point is reached after 41 months (three years and five months) of use, from then on the "perpetual" license is cheaper, with depreciation and interest not taken into account.