Analysis of Real-Time System - External Entity-Relationship Diagram - Lab Report Example

Analysis of Real Time System Name Institution of Affiliation Date 1. External Entity-Relationship Diagram (ERD) Automatic Monitoring and Control System in this case is expected to have the following external entities: I Pumping station: The station has two pumps under the control by the header tank through the AMAC system. II Bottle Washing Plant: This entity interacts with both the AMAC system and the operator. The operator initiates the washing while the AMAC system is responsible for the opening and closing of the various valves. It also conveys clean bottles to the bottle store via conveyor C1. III Bottle Store: Receives bottles from the washing plant and releases them to the filling plant. IV Bottle Filling Plant: Receives bottles from the bottle store via the conveyor C2. AMAC system starts and stops the filling processes. Also, it controls the filling process by opening of valve A and controlling conveyor C2. V Header Tank: Sends readings to AMAC for storage and various actions depending on the evaluation results and mappings against course of actions. VI Data Store: Receives data from the AMAC system. VII An operator: Initiates various conditional actions such as bottle washing, (Peters & Pedrycz, 1998) The diagram above shows the various entities together with their cardinality and modality. The systems contain a number of mandatory relationships because of the entity dependencies. Most entities in the system depend on the success of others, making their relationship not optional but mandatory. The diagram also indicates the various actions by the entities to others. 2. Data and Control Flow Diagrams (DFD/CFDs) AMAC data flow diagram will describe the data flow within AMAC itself and the external entities. It will also show the various transformations on data as well as storage locations. It will trace the travel routes for the data among the entities through the AMAC system (Potse, Linnenbank & Grimbergen, 2002). The control flow diagrams will show the detailed logics of the various plant's processes and the various rules. It will illustrate the various decisions within the system through the decision nodes which goes through a number of logical decisions (Humphrey, 1995). The above data flow diagram shows the various entities and processes which leads to data manipulation. Starting from the header tank, which is one of the sources of data into the system. Also, an operator also introduces inputs to the system through operator's console. AMAC system receives this data and uses in it accordingly to initiate various courses of actions. The operator also initiates various actions directly through issuing of a set of instruction to the system without necessarily going through AMAC. 3. Process specifications (PSPECs) Process specification refers to a way of documenting, analyzing and explaining the logics applied in the decision making processes within a system. It also entails the formulas applied in the generation of output from a set of input set. Process Specifications for AMAC will flow down to a specification of regulatory rules and procedures (Ghezzi, Jazayeri & Mandrioli, 2002). This specification aims at reducing any form of ambiguity in the system and will allow the Muddy Springs Water Co. fraternity to get full descriptions and understanding of the various activities and their execution during water bottling. Finally, the specification will allow validation of the system design alongside data flow diagrams and the data dictionaries (Pressman, 2005). The following are various processes for the AMAC system and the external entities: a Water Pumping: Water is pumped from the pumping station to the Header tank. This happens under various conditions. First, there are two pumps which are controlled by the header tank. AMAC starts one of the pump on drop of water level below 2.2M. If the water level continues dropping past 1.5M, the second pump (B) is started by the AMAC. If water level rises past 3M, both the pumps are closed. After every 30 seconds, the flow rate readings are taken. Pseudo code: initialize water level initialize flow rate initialize time (seconds) if water level drops below 2.2M Start Pump A if water level drops below 1.5M start Pump B else if Water level rises above 3.0M stop Pump A and B while level below 3.0M if time = time+30 Take flow rate reading b Bottle washing: This is done under batch like conditions. When the the batch is ready, the operator initiates the washing process. The AMAC ensures that valves, B, C, E and F are always opened while valve D remains closed. When the the washing process is completed, valve C is closed until the next batch is ready. The clean bottles are then conveyed via conveyor C1 to the bottle store. When the store becomes full, the conveyor is stopped until such a time that there will be room available for more bottles. Pseudo code: if batch is ready while Open: valve B, C, E, F and Close: valve D start the washing(operator) if washing completed Close valve C while store not full convey bottles via C1 to store Stop the conveyor c Bottle filling: This process is under the control of AMAC. It starts and stops the bottle filling process. The conveyor C2 and valve A, must be running and opened conservatively during the filling process. The filling process is stopped when header tank level is too low, or high. It can also be stopped when the bottle store is empty. And finally during routine maintenance or when a command is issued by the operator. During the filling process, the following readings are taken: Starting and stopping time The reason for the action The bottle filling rate Pseudo code: initialize routine maintenance start conveyor C2 open valve A initialize start time initialize stop time initialize filling rate while conveyor C2 and valve A start bottle filling (AMAC) if start time+1 take filling rate if header tank level too low or high stop the filling processed if the bottle store is empty stop the filling processed if operator stop instructions stop filling processes while routine maintenance stop filling process d Data Storage: Various reading taken by the AMAC system are recorded in the database. Also, a number of initializations are also saved in the database for use by the system. References Ghezzi, C., Jazayeri, M., & Mandrioli, D. (2002). Fundamentals of software engineering. Prentice Hall PTR. Humphrey, W. S. (1995). A discipline for software engineering. Addison-Wesley Longman Publishing Co., Inc.. Peters, J. F., & Pedrycz, W. (1998). Software engineering: an engineering approach. John Wiley & Sons, Inc.. Potse, M., Linnenbank, A. C., & Grimbergen, C. A. (2002). Software design for analysis of multichannel intracardial and body surface electrocardiograms.Computer methods and programs in biomedicine, 69(3), 225236. Pressman, R. S. (2005). Software engineering: a practitioner's approach. Palgrave Macmillan. Read More