- 85 - PAS 62559IEC:2008(E) Step by Step Analysis of Function Describe steps that implement the function. If there is more than one set of steps that are relevant, make a copy of the following section grouping (Preconditions and Assumptions, Steps normalseguence,andStepsalternateorexceptionalseguences).ifmorestepsareneededthan are in the Step Table, add entire Steps (not justanother row). C.2.1 Preconditions and Assumptions Describe conditions that must exist prior to the initiation of the Function, such as prior state of the actors and activities. Identify any assumptions, such as what systems already exist, what contractual relations exist, and what configurations of systems are probably in place. Identify any initial states of information exchanged in the steps in the next section. For example, if power HNEANHIALEDYOOK SPLYBURAU system data is being monitored by a SCADA system, a precondition to this particular activity might be"normal monitoring of normal power system activities is taking place". Actor/System/lnformation/Contract Preconditions or Assumptions Time Synchronization Device Prior to of synchro-phasor measurements, the publication underlying sampling c clock must be synchronized to the other clocks in the system. Communication interface Prior to publication of synchro-phasor measurements, the communication interface must be initialized. Phasor Phasor publication enabled publication is enabled after the sampling clock is synchronized and the communication interface is ready SUIP - 86 - PAS62559@IEC:2008(E) C.2.2 Steps - Normal Sequence Describe the normal sequence of events, focusing on steps that identify new types of information or new information exchanges or new interface issues to address. Should the sequence require detailed steps that are also used by other functions, consider creating a new"sub"function, then referring to that"subroutine”in this function.Remember that the focus shouldbeless onthe algorithmsof theapplicationsandmoreontheinteractionsandinformationflowsbetween "entities", e.g. people, systems, applications, data bases, etc. There should be a clear correlation between the narrative and these steps.The entries in the steps are: No.: This could be simple "1, 2, 3" or could include identification of parallel steps if this is relevant,e.g."1a,1b,2,3a,3b,3c" Event: The event that starts the step. This might be completion of the previous step, a human requesting the function, data being reported periodically, or a power system EDBYBKSPLYBURU. event. Description of Process or Activity: This describes what action takes place in this step The focus should be less on the algorithms of the applications and more on the interactions and information flows between “entities", e.g. people, systems, applications, databases,etc. Information Producer: This identifies the producer or source of the information. This shouldbeoneoftheActorsidentifiedabove Information Receiver: This identifies the receiver of the information. This should also be oneoftheActorsidentifiedabove. Information Exchanged: This describes briefly the information to be exchanged: input to RANCHI the function from some external source that is not described in this Use Case, internal to the function(although could bebetween different applications and systems within the function), output from the function that will be used by other entities not included in this UseCase GAL Configuration: Locations, distances, communications layout, media, network bandwidth, existing protocols, numbers of devices, systems, volume of data items, expected growth, etc. Quality of Service Requirements: Availability, acceptable downtime of different components, recovery, backup, frequency of data exchanges, flexibility for future changes, response times, latency of data between detection and its display or action, Security Requirements: Authentication of user, confidentiality, integrity, prevention of denialofservice,non-repudiation oraccountability,errormanagement D