I am trying to figure out how to calculate a projected value for our goals.
Each of our sales persons is assigned an annual goal for 2014, say 60 units. Let's say, as of today, one sales person has sold 5 units.
How would I calculate, assuming everything trends the way it currently is, their projected actual value for year end?
I'd like to show them how they are trending.
Pace = 5 units completed / 16 days
Projected Yearly Outcome = pace * 365
*Note: this example is counting physical days
If you want more accurate results then you need to track this over time (months) and take the average of their paces then just simply multiply it to get the yearly estimate. Keep in mind this is just math so there is no intelligence such as Christmas and New Years where the office could be closed for a week or more. It may also make more sense to look at this in terms of working days then physical (calendar) days.
You have two data points: $0$ units sold as of the beginning of the year, and $5$ sold as of $1/16$. That's $5$ units in $16$ days, so they'll get through their $60$ units in $16 \cdot 12 = 192$ days, or about mid-July.
That assumes that their sales rate remains constant with what we observe. Every day they go without selling, we would tack on an extra $12$ days to meet the goal.
Or, we can look at the remaining sales left against the time left in the year: $55/350$. This means that the person will need to sell one unit every $350/55$ days, or about one per week. Since the person has already sold more than two per week for the first sliver of the year, this is a good thing.
You can get fancier if you have more current sales data or more historical data.
Units completed at the End of the Year is 114.0625
– bkorzynski Jan 16 '14 at 21:13