Types of Hierarchy Trees

SCOPE has four types of Hierarchy Trees: two of which model the functionality to be delivered by the software and must be created in order to measure functional size: these two are:

Function Hierarchy Tree - - models what the software does. It has two levels of nodes.

  1. Functions: record the functional areas into which the software’s functionality can be decomposed.
  2. Processes: record the lowest elementary work task that the software is required to complete. This is the node level that is assessed for its function point weighting.

Data Hierarchy Tree - – models the data that the software is required to store and access. It has four levels of nodes.

  1. Data Group Folders: - - allows the cataloguing of Data Groups into folders for documentation purposes. This level of grouping corresponds to the Function Groups on the Function Tree; it is just used for modelling purposes and not considered for the function point count.

  2. Data Groups: - - record the logical groupings of data at the level of an ‘entity’ or ‘object’. This is the node level which is assessed for its function point weighting.

  3. Record Element Types (RETs) - - record the sub-groupings of the fields to be stored within the Data Group.

  4. Data Element Types (DETs): - - record the fields to be stored within the data group. If there are no sub-groupings of fields (i.e. no RETs)then they may be recorded directly under Data Groups, if they belong to a sub-grouping then they are recorded under their related RET.

The other two Hierarchy Trees do not contribute to functional size, instead they enable the functionality within the Function Hierarchy and Data Hierarchy to be annotated and dynamically grouped for analysis. These other two trees are:

Notes Hierarchy Tree - - models related textual information that needs to be cross-referenced to the software’s functional and data nodes or attribute nodes. Notes act in a similar way to a ‘footnote’ or ‘comment’ and provide annotation to other tree nodes. The Notes Hierarchy has two levels of nodes.

  1. Note Sets: - - record the names of the groupings of textual information such as ‘Specifications Documents’.

  2. Notes: - - record the textual information to be cross-referenced, e.g. under the Note Set ‘Specification Documents’ each Note would map functions and data groups to specific sections within the functional specification document.

Attribute Hierarchy Tree - – enables categories to be set up that can be used to selectively identify, characterise and group either software Functions, Data Groups or Notes. It has two levels of nodes.

  1. Categories: - - record the names of the groups of characteristics, e.g. “Implementation Priority Ratings”, “Specification Quality”.

  2. Attributes: - - record the different types of characteristics you may want to assign to your software Functions, Data Groups or Notes. Attributes can be of two types: Standard attributes and Numerical attributes. Numerical Attributes enable you to quantify your functional model eg. selectivlty apply productivity rates so you can estimate hours to develop, apply NESMA impact factors, do earned value reporting etc.

E.g. if at the group level the Category was “Implementation Priority Ratings” then the Attributes could be:

E.g. The ‘Specification Quality’ Category could have Attributes such as:

Each software Process could be selectively characterised for priority and Specification Quality and then the relative size of each attribute grouping or the combined attribute grouping determined using the Filter Mode function. E.g. “Mandatory – High Priority” functionality can be selected and analysed separately and found to be 100 function points of a total of 150 function points. If the Attribute “Complete” is also included in the Filter then the selection is reduced to be only 75 function points. That is, of the Mandatory – High Priority functions only 75 functions points of the total 100 functions points have a “Complete” specification.

SCOPE enables more than one attribute within any Category to be Linked to any single node on another tree. E.g. a Process may exhibit the characteristics of more than one Attribute in the same Category and Linked to them all. For example if you had a category called Country Installed and it had attributes called USA, Europe, Australia, Japan. If a process was planned to be implemented in all countries then it could be linked to all attributes. A process can be linked to attributes on one or many categories. For example this allows you to report the Functional Size of the ‘Mandatory- High Priority ‘functions and data that had been ‘Completely’ specified and installed in Australia and Japan.

How are Attributes different to Notes?

All nodes in any of the four SCOPE Hierarchy Trees can be Linked to another node in any of the other three trees, thus providing a multi-dimensional documented model of your software.