COSMIC Sizing Forums COSMIC Size measurement Measurement Scope

This topic contains 3 replies, has 2 voices, and was last updated by  Sameer Majithiya 7 months ago.

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  • #6088

    Sameer Majithiya
    Participant

    Hello,

    Can someone elaborate on one of the rules of Measurement Scope (page 22 of MMv4.01) – ‘The scope of any one measurement shall not extend over more than one layer of the software to be measured’? What does it signify?

    Thanks in advance.

  • #6089

    Charles Symons
    Participant

    Sameer, the rules are very simple
    – For the software you want measure, you must define the layer of the architecture in which it is located.
    – Then the scope of the sofware you want to measure must be wholly confined to that layer (this software may, of course, interact with software in other layers)
    As an example, if you want to measure the three components of an application, seen as ‘view’ b), as in Figure 2.4 of the Measurement Manual, you must measure the sizes of the UI, BR and DS components separately because they are in different layers of the 3-layer architecture.

    Then, if it happens that you want to know the total size of the UI + BR components, that may be calculated, but you cannot just simply arithmetically add the two individual sizes. You must eliminate the size contribution of the X/E pairs between the the components from the arithmetic sum of the two sizes.
    A related rule is that a functional process of e.g. the UI component being measured cannot extend over into the BI layer (It can issue X’s and receive E’s from the BI layer, but all its processing takes place within the UI layer.)
    With these rules, and documenting the layer of any piece of software being measured, future users of the measurement will know how to interpret it and how, if needed, its size can be aggregated with other sizes.
    I hope this is clear

  • #6093

    Sameer Majithiya
    Participant

    Hello Charles,

    Thank you for the clarification.
    But just in case I have a functional process which passes through multiple layers, lets say UI and BR then how should we record it? It may happen that for some applications, database access is through BR layer and not directly from UI. In that case, every functional process which has Read/ Write functionality shall pass through BR. So with this rule, are we saying that, this functional process should be considered as if it is a separate functional process in each of the layers?
    This basically implies that this FP shall have two parts (Not sure about this as it breaks the fundamental rule that FP is an elementary part of a FUR) – FP1 in UI with 4 data movements (2 pairs for Es and Xs apart from Triggering entry) and FP2 in BR with 3 data movements (a pair of E and X, and a R/ W).
    In that case, how can we map it to the rule d) of Functional process mentioned on page # 41 of MM4.0.1 as it may not satisfy the entire FUR ?

    Thanks once again for your help.

  • #6108

    Sameer Majithiya
    Participant

    Hello,

    Can anybody help me with the above query?

    Thanks in advance.

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