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SC.4 Use of Off-the-Shelf Products  

  SZ.4 Einsatz von Fertigprodukten

Contents  
  • SC.4.1 Sequence Description for the Activities in Submodel SD
  • SC.4.2 Cooperation with the Remaining Submodels
  •       SC.4.2.1 Cooperation with Submodels SD and PM
  •       SC.4.2.2 Cooperation of Submodels SD and QA
  •       SC.4.2.3 Cooperation of Submodels SD and CM
  • SC.4.3 Criteria for the Selection of the Scenario
  • Links to the V-Model Mailinglist
  • SC.4.1 Sequence Description for the Activities in Submodel SD

    The integration of off-the-shelf products (available, suitable function units for the project) into a System are based on the idea to reduce the development costs and efforts by using already existing modules (SW and HW).

    Off-the-shelf products may have different origins:

    If they meet the defined requirements these products can be applied on all levels of the product structure of the V-Model.

    Using off-the-shelf products within the scope of an incremental development has been illustrated in Figure SC.4.

    Preliminary Remarks:

    Figure SC.4
    Figure SC.4: Sequence of SD Activities when Off-the-Shelf Products are Used

    Time T 0-Start

    Initialization of the project and begin of activities with regard to contents of submodel SD.

    Time T 1-Assessment with Regard to Off-the-Shelf Products to be Used

    As a result of activity SD1.2 - Description of Application System, a preliminary system description is available describing the core and the entire functionality of the System.

    For some fields identified in activity SD1.5 - User-Level System Structure (first increment) the user-level requirements are partly complete (field 1), other parts are incomplete (field 2).

    Together, the results of activities SD1.2 - Description of Application System and SD1.5 - User-Level System Structure represent the User Requirements that are available in a first version (User Requirements version 1).

    The User Requirements must be detailed enough to achieve the following goals:

    As a result of activity SD2.1 - Technical System Design, the fields of the first increment must be described (in System Architecture and Technical Requirements) during the technical realization.

    The individual fields are detailed and specified to the degree necessary for the first productive system version. The individual fields can be refined and completed in later levels.

    The market survey realized within the scope of the feasibility study shows that parts of the User Requirements can be covered by commercially available products. The evaluation of the off-the-shelf products (in activity PM2 - Placement/ Procurement) that may be used prove, however, that none of the off-the-shelf products meets all the defined User Requirements. The realization of a requirement control was decided on within the cope of a phase review (activity PM6 - Phase Review). During the requirement control, suggestions for a modification/reduction of requirements will be defined. The results of the requirement control are integrated into the User Requirements (User Requirements version 2). If necessary, a modification of the system architecture is also required. The User Requirements are the basis for the criteria catalogue to be generated in the PM; this catalogue is used for the selection of suitable off-the-shelf products.

    Time T 2-Integration of Off-the-Shelf Products

    At the time of T 2, the off-the-shelf products obtained by the PM have been integrated into the first increment. All required assembly tasks have been realized. After completion of the integration, the first increment is made available to be used.

    Time T 3 to T N-1-Further Increment Levels

    At the time of T 3, a refined version of the preliminary system description is available as a result of the repeated realization of activity SD1.2 - Description of Application System. Normally, the refinements affect the entire functionality of the System that was defined at the time of T 1. They are a specification of the requirements. However, these refinements may also lead to a new field.

    The user-level requirements are defined for the parts of the second increments. In this connection it is possible to re-describe fields that were not taken into consideration before, and to refine fields that were already available. The first feedback after using the first increment will be taken into consideration.

    The User Requirements thus available in a second version are the beginning of the refinement and completion of the System Architecture and the Technical Requirements.

    The requirements realized in the second increment cannot be covered by off-the-shelf products. The implementor, e. g. a contractor, enlarges the already productive system version 1 by newly added parts and integrates them within the scope of the integration process. It may also be possible that system version 1 has to be changed during the integration tasks. When the second increment has been completed, it is also made available to be used.

    These steps will be repeated for each increment.

    Time T N-Conclusion of the System Development

    At the time T N, User Requirements, System Architecture, and Technical Requirements are complete and available in a consistent version. After the realization of the last increment it is made available to be used. The complete System is now applied.

    SC.4.2 Cooperation with the Remaining Submodels

    SC.4.2.1 Cooperation with Submodels SD and PM

    The procuring of the off-the-shelf products is realized in submodel PM (activity PM2 - Placement/ Procurement). Because of competition, it is necessary to get offers from different manufacturers. These must be evaluated. The required assembly measures have to be defined in connection with the evaluation of the offers.

    In case none of the offered off-the-shelf products meets all of the defined selection criteria, a phase review will decide (activity PM6 - Phase Review) about the necessity of a requirement control.

    SC.4.2.2 Cooperation of Submodels SD and QA

    Meeting the requirements expected of an off-the-shelf product is assessed and evaluated during the evaluation of the offers (activity PM2 - Placement/ Procurement). Therefore, the explicit assessment of the off-the-shelf products within the scope of submodel QA is not necessary. The realized assembly measures must be assessed according to the regulations of submodel QA, and also within the scope of the tender documents generated in activity PM2.

    SC.4.2.3 Cooperation of Submodels SD and CM

    With regard to configuration management, each off-the-shelf product must be treated like an internally developed product. With regard to the change management it is necessary to note that the improvement is influenced by the manufacturer in question. Normally, the modification of User Requirements has no impact on the further development of the final product.

    SC.4.3 Criteria for the Selection of Scenarios

    The following list of advantages and disadvantages and the listing of the most important requirements support the decision-making with regard to the use of off-the-shelf products.

    Advantages:

    Disadvantages: Requirements: The individual advantages and disadvantages mentioned must be investigated and evaluated. They cannot be applied to all projects. For example, a modification of the organization based on the use of off-the-shelf products may have positive effects and improve the effectiveness of the organization.
    Note:

    (1) It is possible that new user-level fields are added in the course of development. This can be problematic for contractual reasons.

    (2) Product development is predominantly driven by the marketplace, not by user requirements.

    Links to the V-Model Mailinglist

    Mail 0344 - Re: Einsatz von COTS-Produkten
    Mail 0342 - Einsatz von COTS-Produkten
    Mail 0295 - Re: Szenario "Einbinden von Fertigprodukten"

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