LFL at equivalent date.
The performance of a store network is measured by the progress of indicators compared to a reference period (most often year - 1, or year - 2) it can be non-comparable NC (without any filter in term of store) or comparable and in this case we will use the abbreviation of LFL means Like For Like.
This notion is quite simple, it’s based on store and date.
a store is comparable if there is at least one sale or return or a Goal on both dates (current and historical).
One day comparison
To have a comparable date the comparison date used is the date of the previous period (Y-1, Y-2 or CY) with the equivalent weekday.
Example :
Thusday May 7, 2021 is compared in LFL to Thusday May 7, 2020.
Friday April 30, 2021 is compared in LFL to Friday May 1, 2020.
February 2021 from Monday February 1, 2021 to Sunday February 28, 2021 is compared to the period from Monday February 3, 2020 to Sunday March 1, 2020.
Comparison over a period
As part of a date period, ONLY the dates when the same store has sales on both days (current and historical) will be considered in the LFL.
Example :
We analyze the turnover of store X, from February 1 to 7 on Y vs Y-1.
Store X is open 5 days in Y: Tuesday, Wednesday, Thursday, Friday and Saturday.
Store X is open 3 days in Y-1 on the comparison dates: Monday, Tuesday and Thursday.
The LFL from February 1 to 7 will therefore have an LFL comparison based on only two days Tuesday and Thursday.
LFL at calendar date
In some cases it is necessary to make a comparison on dates having the same calendar date of comparison. The store may be comparable but the constraint to keep the same day of the week is no longer being respected in calendar mode so the commercial performance can no longer be considered comparable.
One day comparison
In “calendar” comparison, the comparison date used is the date of the previous period (Y-1, Y-2 or CY) with the same equivalent calendar day.
Example :
Thusday May 7, 2021 is compared in LFL to Thusday May 7, 2020.
Friday April 30, 2021 is compared in LFL to Thusday April 30, 2020.
February 2021 from Monday February 1, 2021 to Sunday February 28, 2021 is compared to the period from Saturday February 1, 2020 to Saturday February 29, 2020.
Comparison over a period
For a date period, the comparison is performed on the total number of days for both current and historical period (which can be different). The result is therefore global and cannot only be considered as a commercial performance but will also integrate some calendar effects caused by the non-comparability of days: example the policy of opening on Sundays and public holidays, the number of Saturdays, etc.
Example :
We analyze the sales of a country in 2021 February in CALENDAR mode.
In calendar we will have the sales of stores over the two periods of February 1 to 28, 2021 and February 1 to 29, 2020.
Note that the month of February 2021 has 28 days and 4 Saturdays while the month of February 2020 has 29 days and 5 Saturdays, the value of the comparison is therefore very unreliable commercially and not recommended.