1 / 5

Broad Strategies for identifying System Requirements (Davis, 1982)

Broad Strategies for identifying System Requirements (Davis, 1982). The basic strategies… …ask users … derive from an existing system … derive from a ‘formal’ analytical procedure or model … derive by experimentation and evolution. Ask Users :

lilianna-valerian
Download Presentation

Broad Strategies for identifying System Requirements (Davis, 1982)

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Broad Strategies for identifying System Requirements (Davis, 1982) The basic strategies… …ask users … derive from an existing system … derive from a ‘formal’ analytical procedure or model … derive by experimentation and evolution Ask Users : OK for a stable system with a well-understood structure (e.g. typical admin-type applications) Not OK if …excessive anchoring …excessive concreteness … excessive recency could limit users’ vision of the new system

  2. Excessive Anchoring? An inability to see how things might be different from the present. Excessive Concreteness? An inability to take an abstract view. Excessive Recency? Being over-influenced by recent problems or events. Derive from an existing system in same or different organisation : OK where there are satisfactory precedents. But anchoring remains a danger. Derive from a ‘formal’ analytical procedure or model : Use when major change is needed and anchoring/recency/concreteness could be a problem Use as a check on first two strategies.

  3. Some examples of ‘formal’ procedures/models ...Critical Success Factor Analysis (CSF) … Business process/data modelling and redesign (e.g. ERP, BPR, SSADM) …Decision Analysis (identify key decisions develop algorithms identify information needs) … Normative models like BIAIT “Bill or accept cash?” “Immediate or future delivery?” “Need to keep history of customers’ purchases?” “Rent or sell?” “Make to order or to stock?” “Fixed or negotiated prices?” … Strategy Set Transformation

  4. Discover requirements by experimentation and evolution : Use when no exemplar exists and no model or ‘formal’ procedure can be guaranteed to deliver the goods and/or where needs are changing. Davis’s big point... Uncertainty about what’s needed... Low Ask users Derive from an existing system Derive from an analytical procedure/model Derive by experimentation / evolution High

  5. What factors contribute to uncertainty about what’s needed? • Bad organisational factors e.g. nasty politics, unclear roles, dissagreement, diverse users • Very complexapplication • Inexperienced users • Inexperienced analysts • etc…... Examples... Insurance company reserving system. Standard costing system for bakery. Reference : “Strategies for Information Requirements Determination” G.B. Davis, IBM Systems Journal, Vol.21(1), 1982, pp.4-30.

More Related