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# Usage
```
 ,' ,-_-. '.
((_/)o o(\_))
 `-'(. .)`-'
     \_/

Copyright (C)  2019-2020  Marco Bresciani.

Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.3 or
any later version published by the Free Software Foundation; with no
Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.
A copy of the license is included in the section entitled "GNU Free
Documentation License".
```
The whole spreadsheet, in LibreOffice Calc format, contains these
sheets:
* [Notes](#notes)
* [WorkItems](#workitems)
* [CFD](#cfd)
* [Lead Time](#lead-time)
* [Little's Law](#littles-law)
* [Metrics](#metrics)
* [Distribution](#distribution)
* [Data](#data)

and it can be modified and used following the [GNU General Public
License (GNU GPL)](https://www.gnu.org/licenses/gpl.html).

For daily normal use, [WorkItems](#workitems) should be the only sheet
you need to work on, while all other sheets are there to let you read,
report and visualize metrics.
There are no hidden sheets nor password-protected cells.
The whole spreadsheet is completely available for you, following the
license terms.

Please note that [WorkItems](#workitems) sheet already contains some
data.
Those are sample data to show you how to use and write them.
Feel free to remove (or overwrite) them.

## Notes
The [Notes](#notes) sheet is just a sort of cover page for the whole
spreadsheet with licensing notes and the version number of the release,
for reference.

## WorkItems
For daily usage purposes, [WorkItems](#workitems) is the only sheet you
might need to work on and modify, by adding your own work items data.

The whole [WorkItems](#workitems) sheet is compatible with [Actionable
Agile™ Analytics](https://www.actionableagile.com/) tool (see [Format
for Data File](https://www.actionableagile.com/format-data-file/)):
simply export [WorkItems](#workitems) sheet as CSV (select comma
<`,`> as cell separator and quotes <`"`> for fields) and then
import it in the tool.

As described in the [Format for Data
File](https://www.actionableagile.com/format-data-file/) page, the first
row contains the column names for each of the data fields.
* The first column is an item **ID** field.
* The second column is optional, and it's the **Link** to the item
  location in your online Kanban/Agile/PM tool, if any.
  If not used, the whole column can be hidden.
* The third column is optional (but I strongly suggest to use it), and
  it's the item **Name** (or title or description) field.

The next set of contiguous columns are the sequential steps of your
workflow.
Due to the basic needs of Personal Kanban concepts, they have been set
(and fixed) to **Backlog**, **Next**, **In-progress** and **Done**.
The contents of these columns are the date the item entered each
workflow step.

For standardization purposes, the dates are displayed in ISO8601 format
(`yyyy-mm-dd`) but can be entered in your local format (e.g.:
`dd/mm/yyyy` or whatever), as configured in LibreOffice Calc.

The **Backlog** column contains the date when the work item appears,
when you had a new idea, a new task appears, or anyway when something
potentially doable appears in your work system.

The **Next** column represents the date when the work is definitely
committed by the person/entity that asked for it or when you decide that
the work has to be done.
For example: you may have an idea for a very good book, but this does
not mean that you actually have to write it.
Unless you firmly decide to write it.
This is  called *Commitment point*, the point in a kanban system at
which the commitment is made to deliver a work item.
Before this point, work done supports the decision whether or not to
deliver the item.
After this point, it has been confirmed that the customer wants and will
take delivery of the item, and that the service will deliver it.

The **In-progress** column contains the date when you have started
working on the work item activity.

The **Done** column contains the date when the result of the work item
activity has been delivered/provided to the person/entity that asked for
it.

These above are the mandatory columns for metrics.
There are also optional columns that may help identifying and
categorizing work items and their information:

* **CoS** is the Class of Service of the work item and it should help
  differentiate items based on their Cost of Delay.
  Each class of service has a specific execution policy that the service
  provider agrees to follow.
  Those following are the basic standard classes of service defined in
  [Kanban](https://leankanban.com/shop/kanban-book/) book and predefined
  as available in this sheet.
  If you need other classes of service, feel free to modify the sheet
  according to the license above.
  Traditional Classes of Service can be described as:
    * *Expedite*, has an unacceptable cost of delay and therefore
      requires immediate attention.
      It can be pulled into development, even in violation of current
      WIP limits (even if it shouldn't be).
      > Typically, there can be only one expedite item in the system at
        a time, and teams may set a policy to swarm on that item to make
        sure it moves through the system rapidly.
    * *Fixed date*, describes work items that must be delivered on or
      before a specific date.
      > Typically, the cost of delay of these items is nonlinear and is
        highly sensitive to small changes in the delivery date; these
        must be actively managed to mitigate the schedule risk.
        Therefore, these items are pulled into development when
        necessary to be finished on time.
        Some items may require additional analysis to refine the
        expected lead time.
        Some need to be reclassified as expedite if the team falls
        behind.
    * *Standard*, represents the baseline class of service, applicable
      to work items that are neither expedited nor fixed date.
      Most backlog items should fall into this category.
      > The cost of delay is linear for standard items, meaning that
        value cannot be achieved until delivery occurs, but there's no
        fixed-date requirement.
    * *Intangible* is used for work that goes through the system that
      doesn't directly deliver value to the customer.
      > This is work that needs to be done - but for which it is hard to
        show a return on investment.
        It is a good idea to have some Intangible work going through the
        system.
        It is better to set this aside when an Expedite comes through
        then work with an associated due date or cycle time expectation.

* **WIT** is the type of the work item (Work Item Type) and it should
  help categorize items based on your ideas, needs and concepts.
  Each work item type is specific for the person or team or group that
  define it and for which it has a specific meaning.
  Some examples can be: "work", "home", "children", "taxes" or whatever
  category or main argument you may want to use to aggregate items
  information and types.
  There are no pre-defined WITs in this sheet.

* **Deadline** is usually used for Fixed Date CoS only, and it
  represents the date before which the item shall be completed.
  The column value is anyway optional, even for Fixed Date CoS.
  The content is automatically formatted to ISO8601 standard as
  described above and conditionally formatted with the following rules:
   * today, red background cell;
   * this week, orange background cell;
   * this month, yellow background cell;
   * next month, green background cell;
   * expired completed work item, red text.

* **Blocked Days** represents the total number of days when the work
  item was blocked due to *external dependencies* or events or any
  *system-external* reason for which the item itself was not available
  to work on.
  In order to be properly evaluated, it shall be computed as the
  difference between two dates, plus one.
  That is: if a work item has been blocked today only, the Blocked Days
  column shall count 1, while if the work item has been blocked
  yesterday and today, the column shall count 2, etc.
  It is obviously possible to add multiple blockers, even through
  formulas, by simply adding the intervals and rembering to add 1 for
  each:
  `=(date(2019,8,15)-date(2019,8,12)+1)+(today(2019,3,5)-date(2019,3,3)+1)`
  that represents a blocker from 2019-08-12 to 2019-08-15 (4 days) and
  another blocker from 2019-03-03 to 2019-03-05 (3 days), for a total of
  7 blocked days.

* **Deleted** is the column that contains the date when a work item has
  been considered discarded (while in Backlog) or the work is aborted
  (while in Next or In-progress) and no more bringing value to the flow.

  > *While bug [#109947](https://savannah.nongnu.org/support/?109947) is
    open*, when a work item has to be discarded or is aborted, *you*
    have to write such cancellation date in all remaining columns cells
    and also write the same date in the **Deleted** column.
	With this, the work item will be properly identified as deleted.

* The **Labels** column may contain a set of strings and text
  identifiers (labels) that can be used to further filter, categorize or
  tag the work items in order to better identify and collect their
  metrics.
  As shown in the example data of [Actionable Agile™
  Analytics](https://www.actionableagile.com/) tool, a single label can
  be written as simply as `A` while possible multiple labels can be
  represented as `[A|D|Y]`.
  That tool will take care of using them for filtering purposes.
  This spreadsheet has currently no use for this column, and it can be
  hidden.

All those columns above are properly managed by the [Actionable Agile™
Analytics](https://www.actionableagile.com/) tool as attributes that can
be filtered and grouped.
Filtering by **CoS** or **WIT** or other columns, and applying metrics
to filtered elements is not yet supported in this spreadsheet.

## CFD
The [CFD](#cfd) dashboard sheet has the name tab highlighted in a
different colour to show that it does not contain nor compute data but
represents them in charts.

If not otherwise specified, charts in this dashboard contain or manage
data enough to run the board for ten average Gregorian years (3652
days).

It contains some major metrics charts such as:
* *Cumulative Flow Diagram* (CFD) that shows:
  * a gray line showing the cumulative total number of work items that
  were created (**Backlog**);
  * a red line showing the cumulative total number of work items that
  has been committed (moved to **Next** column) for completion;
  * a yellow line showing the cumulative total number of work items that
  has been worked on (moved to **In-progress** column);
  * a green line showing the cumulative total number of work items that
  has been completed, discarded or aborted (moved to **Done** column).
  There is no visual distinction between actually completed work items
  and work items that have been discarded or aborted.

  The horizontal axis is a timeline and each work item is marked on the
  date of status update.
  The vertical axis represents the cumulative total number of work items
  for such status on the reference date.
  This chart is a representation of the ongoing status of the service
  flow.

  For a detailed description of the behaviours and issues you can find
  with a Cumulative Flow Diagram, take a look at this relevant and
  interesting article by Pawel Brodzinski on his blog: [Cumulative Flow
  Diagram](http://brodzinski.com/2013/07/cumulative-flow-diagram.html).
* The *Daily Run Chart*, is the run chart for the daily values of
  **Backlog** (gray, number of work items waiting), **DR** or Delivery
  Rate (light green, number of daily completed work items),
  **Throughput** (green, number of daily done (completed + aborted)
  work items) and **WIP** (orange, number of ongoing work items).
* The *Backlog Age Distribution* is the distribution chart representing
  the amount of time work items wait in Backlog before being committed.
  The chart includes data from all work items that has been created,
  regardless they are still in *Backlog*, they are in progress or
  already done.
* The *CoS Ratio* chart shows the Classes of Services ratio with respect
  to the total number of work items.
  It uses the four standard Classes of Services, and the colours are
  those defined as examples in
  [Kanban](https://leankanban.com/shop/kanban-book/) book and available
  in the **CoS** column in [WorkItems](#workitems) sheet.
* The *Flow Efficiency* is the run chart for Flow Efficiency
  computations with associated moving averages from the **FE**,
  **NetFE**, **mFE** and **mNetFE** columns in [Metrics](#metrics)
  sheet.

Since the same data are sometimes shown in different charts, in order to
improve readability, the data always (try to) use the same colouring
throughout the charts in this sheet.
So, for example, **mWIP** is always an orange line, both in *Little's
Law* and in *WIP Run Chart*, etc.

## Lead Time
The [Lead Time](#lead-time) dashboard sheet has the name tab
highlighted in a different colour to show that it does not contain nor
compute data but represents them in charts.

If not otherwise specified, charts contain or manage data enough to run
the board for ten average Gregorian years (3652 days).

It contains some charts related to Lead Time metric such as:
* the *Lead Times Scatterplot* chart of completed work items, starting
from the earliest to the current date.
The scatter plot shows:
  * a blue dot for each "Done" work item with the value of its
    corresponding **LT** (Lead Time);
  * a red upward pointing triangle for each work item still in progress,
    with the value of its current **Age** (number of days since it
    entered **Next** state);
  * a red dotted line representing the moving average of the **95th
    percentile** of the **LT** values;
  * an orange dotted line representing the moving average of the **85th
    percentile** of the **LT** values;
  * a yellow dotted line representing the moving average of the **70th
    percentile** of the **LT** values;
  * a green dotted line representing the moving average of the **50th
    percentile** of the **LT** values;
  * a blue dotted line representing the moving average of the **LT**
    values themselves (**mLT**).

  The horizontal axis is a timeline and each work item is marked on the
  completion (**Done**) date while in progress items are marked on
  commitment (**Next**) date.
  The vertical axis represents the number of days: lead time of
  completed work items goes from the commitment point (when the work
  item enters the **Next** column) to the **Done** status (either
  completion or discard); age of ongoing work items goes from the
  commitment point (**Next**) to current date.

  This chart is a representation of how long (**LT**) it takes to get
  things done for individual work items on the kanban board and the
  trends the **LT** has in time.

  Possible uses for scatterplots are:
  * visualize clearly the lead times of the work items, possibly
    filtering them according to CoS or WIT;
  * compare different WITs lead times;
  * forecast the lead time of future work items.

  For a detailed description of the behaviours and ways to read a lead
  time scatterplot, take a look at this article by
  [Kanbanize](https://kanbanize.com/): [Using Scatter Plot to Measure
  and Forecast Cycle
  Time](https://kanbanize.com/kanban-resources/kanban-analytics/cycle-time-scatter-plot/)
  with further details on [Meet the Cycle Time Scatterplot from Premium
  Analytics](https://kanbanize.com/blog/premium-cycle-time-scatterplot/).
* The *Lead Times Distribution* is the chart that represents the
  bin-constrained frequencies of Lead Times for all done work items.
  It plots the frequency of lead times, split in a set of 42 bins from
  the lowest to the highest with an blue dotted line overlay of the
  estimated Weibull distribution for such frequencies, if any.
  The values that are involved are **F(LT)** and **Weibull(LT)** from
  [Distribution](#distribution) sheet.
* The *Throughputs Distribution* is the chart that represents the
  bin-constrained frequencies of Throughput values for all days.
  It plots the frequency of throughputs, split in a set of 42 bins from
  the lowest to the highest with an green dotted line overlay of the
  estimated Weibull distribution for such frequencies, if any.
  The values that are involved are **F(Throughput)** and
  **Weibull(Throughput)** from [Distribution](#distribution) sheet.
* the *Lead Times Detail* charts work items Lead Times splitting them
  according to the time spent in each workflow status.

  For example: if a completed work item has spent 2 days in **Backlog**,
  3 days in **Next** and 12 days in **In-progress**, then the bar for
  such work item will be 17 days long, split in three differently
  coloured sections: a gray part, 2 days long, for **Backlog**; a red
  part, 3 days long, for **Next** and a yellow part, 12 days long, for
  **In-progress**.
  Keeping the same colour-conventions as in the *Cumulative Flow
  Diagram*, this chart shows:
  * a gray vertical bar showing the total number of days a completed
    work item has spent in the **Backlog** column;
  * a stacked red vertical bart showing the total number of days a
    completed work item has spent in the **Next** column;
  * a stacked yellow vertical bar showing the total number of days a
    completed work item has spent in the **In-progress** column.

  These are actual (calendar) days: if a work item has been moved from
  **Backlog** to **Done** in the same day, all column will be 0 (zero),
  but the corresponding Lead Time for such work item will be 1 (one)
  day.

  Since this is a bar chart, it cannot be spread to include 3652 days
  like, say, the *Lead Times Scatterplot* chart because it does not
  automatically scale to skip empty values.
  So, while categories include the whole ten (average Gregorian) years
  set, the values of **Backlog**, **Next** and **In-progress** columns
  have been limited to 42 rows.
  Feel free to increase it, as soon as you have more than 42 work items,
  and remember to increase it further, when work items will increase in
  number.
* *Lead Time Control Chart*, is the chart that, following the principia
  and criteria of industrial control charts (see
  https://en.wikipedia.org/wiki/Control_chart), does a visual
  representation that can be used for statistical process monitoring.
  This can be used to identify special causes, that are working items
  that, for some reason, had a strange behaviour with respect to the
  overall system trend.
  Any observations outside the limits, or systematic patterns within,
  suggest the introduction of a new (and likely unanticipated) source of
  variation, known as a special-cause variation. Since increased
  variation means increased quality costs, a control chart signaling the
  presence of a special-cause requires immediate investigation.
* *WIP Run Chart*, is the chart that shows the ongoing daily **WIP**
    values together with its moving average (**mWIP**) and the weekly
    moving average (**mWIP(7)**), computed only on the latest seven days
    of actual data).
* *Throughput Run Chart*, is the chart that shows the ongoing daily
  **Throughput** values together with its moving average (**mThr**) and
  the weekly moving average (**mThr(7)**), computed only on the latest
  seven days of actual data).

Since the same data are sometimes shown in different charts, in order to
improve readability, the data always (try to) use the same colouring
throughout the charts in this sheet.
So, for example, **mWIP** is always an orange line, both in *Little's
Law* and in *WIP Run Chart*, etc.

## Little's Law
The [Little's Law](#littles-law) dashboard sheet has the name tab
highlighted in a different colour to show that it does not contain nor
compute data but represents them in charts.

If not otherwise specified, charts in this dashboard contain or manage
data enough to run the board for ten average Gregorian years (3652
days).

The dashboard contains some charts related to Little's Law and other
useful metrics such as:
* The *Little's Law*, is the *LT = WIP / Thr* chart that represents the
  three terms of Little's Law.
  Running average of WIP (**mWIP**, orange), computed on actual data;
  running average of Throughput (**mThr**, green), computed on actual
  data; running average of Lead Time (**mLT**, blue), computed as ratio
  between those two values above;
* *I/O speed*, is the chart that represents the running average speed of
  incoming (**mArrival**) and outgoing (**mThr**) work items, in terms
  of average number of work items per day.
  There is also the running average of delivery rate (**mDR**)
  considering only completed work items, without deleted/aborted ones.
* *Blockers*, is the chart that represents the running average
  **Impact** blockers may have in a work item, that is the average
  number of blockers (days) that may happen during a work item lifetime,
  the average **Likelihood** (probability) that a blocker might happen
  during a work item life (on secondary, right-side, Y axis) and the
  average **Risk** that a blocker may represent, as product between the
  two previous values.
* *Little's Law (7 days)*, is the *LT = WIP / Thr* chart that represents
  the three terms of Little's Law.
  Running average of WIP (**mWIP(7)**, orange), computed only on the
  latest seven days of actual data; running average of Throughput
  (**mThr(7)**, green), computed only on the latest seven days of actual
  data; running average of Lead Time (**mLT(7)**, blue), computed as
  ratio between those two values.
  The throughput is represented on the secondary (right-side) Y axis;
* The *Approximate Average Lead Time*, shows the **mLT** value, together
  with the trend of the approximate average lead time (**AALT**), as
  shown by the CFD chart.
  The approximate average lead time is described in chapter 9 of the
  [Actionable Agile Metrics for
  Predictability](https://leanpub.com/actionableagilemetrics) book (as
  Approximate Average Cycle Time) and a practical example is show in
  [Actionable Agile Metrics for Predictability by Daniel S. Vacanti,
  Re-read Saturday Week 10: Flow
  Debt](https://tcagley.wordpress.com/2017/12/23/actionable-agile-metrics-for-predictability-by-daniel-s-vacanti-re-read-saturday-week-10-flow-debt/#more-9151)
  while reviewing and commenting the book itself.
  It can be used to highlight flow issues.
* *Effort Run Chart*, simply represent the inverse of the daily **WIP**
  (`1/WIP`) and, for this reason, shows, each day, the **Daily Effort**
  that is the time theoretically spent, such day, for each ongoing (both
  **Next** and **In-progress**) work item.

  For example: if the **WIP** value is 1, you theoretically spend 100%
  of your time on such work item.
  If you have 2 ongoing work items (`WIP = 2`) means that you
  theoretically spend half of the day on each work item, this means the
  effort for each work item is 50%.
  With 5 work items, your **Daily Effort** for each work item is 20%,
  and so on.

Since the same data are sometimes shown in different charts, in order to
improve readability, the data always (try to) use the same colouring
throughout the charts in this sheet.
So, for example, **mWIP** is always an orange line, both in *Little's
Law* and in *WIP Run Chart*, etc.

## Metrics
The [Metrics](#metrics) sheet contains a set of metrics computed from
the data in [WorkItems](#workitems) sheet.
Mainly, together with a few duplication of information (work item
**ID**, **Name**, and **Done** date) for better reference and
readability, for each row there is a work item with the following
metrics and columns.
These metrics are referred to a single work item, even if there are
others (such has averages), that are more related to the evolution of
those basic metrics.

To easily remember the content length, the formulas in this sheet are
spread till row number 3653, that is enough to manage 3652 work items.
Feel free to increase the formulas coverage by dragging them to cover
more rows, when needed.
* **Backlog**, **Next** and **In-progress** columns that contain the
  number of days spent by the work item in each column.
  If the work item enters and exists a column on the same day, the count
  will show 0.
  If the work iteam has not yet entered a column, that column value will
  be empty, for such work item. In this situation, the value for the
  latest filled column will be computed against the current day.
* the **95%**, **85%**, **70%**, **50%** columns that represent the
  moving percentile of the completed work items Lead Times.
  You can find a description of percentile in
  [Percentile](https://en.wikipedia.org/wiki/Percentile) page on
  Wikipedia.
  For more details, see [Actionable Agile Metrics for
  Predictability](https://leanpub.com/actionableagilemetrics) book.
* **LT** computes the Lead Time for each completed work item.
  That is, **Done** date minus **Next** date plus one.
* **mLT** contains the daily moving average of all the Lead Times of
  the completed work items.
  Please note that this is the plain running average, done
  point-by-point by day.
* **Age** contains, for all not-completed work items, the number of days
  since the work item is in progress (since it entered in **Next**).
* **Blocked Days** contains the total number of days the work item has
  been blocked.
* **Computed Effort**, for a completed work item, considers, for each
  day of the progress life of the work item, the number of parallel work
  items ongoing in the system (that is, the daily WIP).
  e.g. While a single work item counts as 1 day of effort per day, if
  there are two parallel work items (WIP = 2), the actual effort, per
  work item, is 1/2 (or half) day.
  So, summing up all these daily computed efforts, for the whole work
  item lifetime, this column contains the total number of days
  theoretically worked on the work items, blockers included.
* **FE** (or Flow Efficiency) is computed, for each completed work item,
  as the ratio between the lead time minus the blocked days and the lead
  time itself.
  e.g. If a work item has been completed in 13 days but it has been
  blocked for 5 days, its FE is 61.53% that is (13 - 5) / 13.
* **NetFE** (or "Net" Flow Efficiency) is computed, for each completed
  work item, as the ratio between the lead time minus the sum of blocked
  days and days in **Next** column, and the lead time itself.
  e.g. If a work item has been completed in 13 days but it has been
  blocked for 5 days and it has spent 2 days in Next column, its NetFE
  is 46.15% that is (13 - (5 + 2)) / 13.

Those metrics below, instead, are not associated to a single work item,
as per those above, but are actually associated to the completion date
in the same line.
They all are averages computed from values on such completion date and
before, considering all values in those dates.

* **Impact** is computed (as described in [Kanban Maturity
  Model](https://www.kanbanmaturitymodel.com/) book), for a completed
  work item, by summing the total of blocked days of all previously
  **Done** work items (current included), divided by the number of
  work items.
  It represents the average number of blocker days per work item.
* **Likelihood** is computed (as described in [Kanban Maturity
  Model](https://www.kanbanmaturitymodel.com/) book), for a completed
  work item, by counting the total number of blockers of all previously
  **Done** work items (current included), divided by the number of
  work items.
  It represents the average probability of having a blocker per work
  item.
* **Risk** is computed (as described in [Kanban Maturity
  Model](https://www.kanbanmaturitymodel.com/) book), for a completed
  work item, by multipling the Impact and the Likelihood.
  It represents the average number of blocker days that may appear in
  work items.
* **mFE** contains the daily moving average of all the Flow Efficiencies
  of the completed work items, with completion date lower or equal the
  current work item one, if any.
* **mNetFE** contains the daily moving average of all the Net Flow
  Efficiencies of the completed work items, with completion date lower
  or equal the current work item one, if any.

## Distribution
The [Distribution](#distribution) sheet contains some set of data used
for previously described chart.
Specifically, it contains the frequency distributions and percentile
value for **LT**, **Backlog** and **Thr**oughput, as shown in
[CFD](#cfd) and [Lead Time](#lead-time) dashboards.
* The **F(LT)** column contains the frequency related to lead times, the
  number of completed work items that had a lead time less than or equal
  to the **LT(bin)** column value.
  This table column is also plotted as histogram (*Lead Times
  Distribution* bar chart) showing the current distribution of lead time
  frequencies.
* The **F(Backlog)** column contains the frequency related to age of
  elements (days spent) in backlog, regardless they are still in backlog
  (so their age will increase) or they've already been moved to other
  columns.
  This is the number of work items that have/had a backlog age less than
  or equal to the **Backlog(bin)** column value.
  This table column is also plotted as histogram (*Backlog Age
  Distribution* bar chart) showing the current distribution of backlog
  ages frequencies.
* The **F(Thr)** column contains the frequency related to daily
  throughput values, the number of done work items for each day, less
  than or equal to the **Thr(bin)** column value.
  This table column is also plotted as histogram (*Throughputs
  Distribution* bar chart) showing the current distribution of
  throughputs frequencies.
* The Weibull columns (**Weibull(LT)**, **Weibull(Backlog)** and
  **Weibull(Thr)**) contain the computed values of the approximate
  Weibull distribution that mostly resemble the current distribution of
  values described by the **F(LT)**, **F(Backlog)** and **F(Thr)**
  columns.
  These table columns are also plotted as line overlapped to their
  specific distribution bar chart.
  The Weibull distributions are computed from the specific values of
  **Shape (k)** and **Scale (λ)** that have been approximated from the
  **Percentile(LT)**, **Percentile(Backlog)** and **Percentile(Thr)**
  values.
* **Shape (k)** is computed from the 35p and 75p (percentile) values in
  the **Percentile(LT)** column while **Scale (λ)** is computed from the
  35p value and the **Shape**.
  I'd reference to Alexei Zheglov's nice blog post [How to Match to
  Weibull Distribution in
  Excel](https://connected-knowledge.com/2013/08/01/how-to-match-to-weibull-distribution-in-excel/):
  even though my calculations came from a different source (that I can't
  actually remember, but still searching to give it a proper reference),
  the results are similar to those written by Alexei in such post.
* **Mean**, **Variance**, **Median**, **Mode** are computed according to
  default Weibull distribution equation, using values of **Shape (k)**
  and **Scale (λ)**.
  Together with this default values from a Weibull distribution, there
  also are the **UCL** (Upper Control Limit) and **LCL** (Lower Control
  Limit) for control chart purposes as described, again, by Alexei
  Zheglov in [On the Practically Useful Properties of the Weibull
  Distribution](https://connected-knowledge.com/2013/08/01/on-the-practically-useful-properties-of-the-weibull-distribution/).
* **Percentile(LT)** and **Percentile(Backlog)** columns represents the
  current percentile values for Lead Time and Backlog age, the latter
  being the number of days a work item remains in the Backlog (since it
  has been created) before being took in charge and worked on;
* The **CoS** table shows the Classes of Services ratio with respect
  to the total number of work items.
  It uses the four standard Classes of Services, and the colours are
  those defined as examples in
  [Kanban](https://leankanban.com/shop/kanban-book/) book.
  It's the source of the *CoS Ratio* chart in the [CFD](#cfd) dashboard
  sheet.

## Data
The *Data* sheet is the daily representation of the whole board, with
reference metrics needed for each day (**Date** column).
Together with the daily number of work items for each column
(**Backlog**, **Next**, **In-progress**, **Done**), the sheet contains:
* the daily number of **Deleted** work items.
* the daily *Delivery Rate* (**DR**), the number of completed work items
  for the day, that is the number of work items moved to *Done* column
  and not deleted/discarded.
* the moving average delivery rate since the initial period (**mDR**).
* the daily **WIP**, the number of currently ongoing work items
  (**Next** plus **In-progress**).
* the moving average WIP since the initial period (**mWIP**).
* the moving average WIP of the latest seven days (**mWIP(7)**).
* the average lead time (**mLT**) computed as **mWIP** / **mThr**.
* the average lead time (**mLT(7)**) computed as **mWIP(7)** /
   **mThr(7)**.
* the theoretically (computed) current **Daily Effort** per work item,
  as the multiplicative inverse of **WIP** (1 / **WIP**).
* the daily current **Thr**oughput as the number of done work items for
  the day, that is the number of work items moved to *Done* column.
* the daily **mArrival** and **mThr** moving averages rates for work
  items as described in [Actionable Agile Metrics for
  Predictability](https://leanpub.com/actionableagilemetrics) book (as
  "Incoming" and "Outgoing"), together with the weekly **mThr(7)**;
* after a duplication of the **Date** for better readability, the set of
  cumulative daily data of work items for each column (**Backlog**,
  **Next**, **In-progress**, **Done**);
* the Approximate Average Lead Time (**AALT**), computed as described in
  [Actionable Agile Metrics for
  Predictability](https://leanpub.com/actionableagilemetrics) book.

This chart contains data rows till spreadsheet row number 3653, that is
enough to run the board for ten average Gregorian years.

## Appendix

### GNU Free Documentation License

Version 1.3, 3 November 2008

Copyright (C) 2000, 2001, 2002, 2007, 2008 Free Software Foundation,
Inc. <https://fsf.org/>

Everyone is permitted to copy and distribute verbatim copies of this
license document, but changing it is not allowed.

#### 0. PREAMBLE

The purpose of this License is to make a manual, textbook, or other
functional and useful document "free" in the sense of freedom: to
assure everyone the effective freedom to copy and redistribute it,
with or without modifying it, either commercially or noncommercially.
Secondarily, this License preserves for the author and publisher a way
to get credit for their work, while not being considered responsible
for modifications made by others.

This License is a kind of "copyleft", which means that derivative
works of the document must themselves be free in the same sense. It
complements the GNU General Public License, which is a copyleft
license designed for free software.

We have designed this License in order to use it for manuals for free
software, because free software needs free documentation: a free
program should come with manuals providing the same freedoms that the
software does. But this License is not limited to software manuals; it
can be used for any textual work, regardless of subject matter or
whether it is published as a printed book. We recommend this License
principally for works whose purpose is instruction or reference.

#### 1. APPLICABILITY AND DEFINITIONS

This License applies to any manual or other work, in any medium, that
contains a notice placed by the copyright holder saying it can be
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#### 2. VERBATIM COPYING

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#### 3. COPYING IN QUANTITY

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#### 5. COMBINING DOCUMENTS

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#### 6. COLLECTIONS OF DOCUMENTS

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#### 7. AGGREGATION WITH INDEPENDENT WORKS

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#### 8. TRANSLATION

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#### 9. TERMINATION

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#### 10. FUTURE REVISIONS OF THIS LICENSE

The Free Software Foundation may publish new, revised versions of the
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#### 11. RELICENSING

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### ADDENDUM: How to use this License for your documents

To use this License in a document you have written, include a copy of
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