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Part 2. Sequence Diagram a) In your own words, briefly describe what is modelled in a Sequence Diagram, and how Sequence Diagrams can be useful in systems analysis and design (max 100 words, +/10% tolerance). b) Draw a Sequence Diagram for the use case in your diagram that corresponds most closely to the use case 'Allocate Truck to Driver'. This should include all control, boundary and entity objects involved in the scenario and the sequence of interactions that take place in order to meet the system requirements. Your diagram should be drawn using the Enterprise Architect software, and copied and inserted as a picture into your document. c) Write a brief summary of the decisions made whilst drawing the diagram, and your reasons for making those (max 150 words, +/10% tolerance). Swift Distribution Ltd. Management System Swift Distribution Ltd. (SDL) is a medium-sized haulage company specialising in collecting and delivering goods for customers throughout England, Scotland and Wales. It is trying to survive in difficult industry conditions, competing against larger haulage firms and within an environment of rising fuel costs and heavy taxation. By providing an efficient service and personal attention, the company has built up a stable customer base. The owners of SDL are concerned that their market share is under threat; larger haulage firms are able to offer more competitive prices and the fast and efficient service is being compromised by road congestion. They have recognised that the company needs to hold down costs by seeking to save fuel and to save time by having available better, quality information about road conditions, while maintaining their reputation for personal and friendly service. In addition to taking these measures they have sought to enter into agreements with larger business partners in order to achieve stability in their customer base. In recent months a contract has been agreed with a company called Home Electronics Co-Operative (HECO). This is an organisation which acts for independent electronics retailers allowing the bulk purchase of electrical goods which enables them to buy electrical goods at prices competitive with those of the big bulk buyers such as department stores and the high street chains. HECO also records stock kept at the independent retailers' premises which allows them to hold lower stock levels and to fulfil orders by "borrowing" stock from the other retailers when they have sold out of particular items. SDL's role in this agreement is to provide for HECO the collection of stock from the warehouses of the national electrical distributors and to deliver it to the independent retailers. They will also collect and deliver the inter-retailer "stock loans". To achieve these ends the owners of SDL have decided to invest in a new integrated information system to replace the current disparate customer, order, driver and vehicle management systems. The new system will be required to maintain records of current customers and the business they generate, including the production of invoices and management of customer accounts. Additionally, the new partnership with HECO necessitates the new SDL system will be required to download independent retailer records from the HECO system together with details of collections and deliveries from distribution warehouses and retailers; and from retailer to retailer. It will also maintain records of the haulage vehicles, including taxation, maintenance and mechanical faults reported by drivers. It will also need to maintain driver records (although the payroll will continue to be contracted out); this will include personnel records, license information and driving hours. The main innovations for the new system will include a business to business ( B2B) link between the SDL servers and the HECO servers in order to transfer stock collection and delivery information; and a GPS-based (global positioning system) logistics system to optimise vehicle routing and save both fuel and time. It is envisaged that requests for stock originating from retailers are sent to HECO; the nearest associate retailer holding that stock item is located; and the location of the "donor" and "recipient" retailers together with stock item details are to be transferred to the SDL servers. From here this information is to be immediately transmitted to an appropriate driver for collection and delivery. By using a GPS the head office could know the location of every vehicle at each point in time. Putting this together with information about the loads each vehicle is carrying and the loads they are scheduled to pick up and deliver, work could be dynamically re-scheduled and drivers directed to the appropriate place to make the most efficient use of the vehicle fleet. Added to this, information about road conditions could be used to inform drivers what route they should take and what trouble spots to avoid, thus shortening journey times. The main users will be: - Customer Service Staff- Customer Service Staff are primarily responsible for dealing with SDL's customers. They create delivery job records; create/maintain customer records; record card payment details; and can track parcels. It is envisaged that in the new system they will also be responsible for downloading the HECO delivery list. At very busy times they may also assist the Finance Clerk in sending out invoices to business customers. - Finance Clerk- The Finance Clerk has responsibility for dealing with customer payments. For business customers (including HECO) this involves sending out invoices and processing invoice payments; and for individual members of the public who use the SDL courier service in involves processing their card payments. Logistics Planner- Logistic planners are responsible for creating the delivery schedules for each truck's daily deliveries. They will need to download the HECO delivery list to facilitate this. Where a "collect and deliver" request comes from HECO they will identify individual trucks and modify its schedule to incorporate this job. - Fleet Manager- The Fleet Manager ensures that the trucks are roadworthy and so is responsible for the maintenance of the truck service record. Other responsibilities include the maintenance of driver records; the allocation of a specific truck to a specific driver; and in order to ensure drivers stay within the legal limits for working, for the checking of odometer readings. Driver- Drivers are issued with networked handheld devices so that they may update the status of consignments dynamically. They are responsible for setting the start of their driving period; setting the end of the driving period; recording job collections and job deliveries; and acknowledging schedule modifications. - Requests for delivery services will be received from customers directly on line via the Internet, by telephone or by email. Delivery service requests for HECO are received by connecting to the HECO server system and executing a download of the necessary collection/delivery details for the various consignments. Requests via the Internet result in the direct creation of the delivery job record, but for orders received by telephone, by email or by download, a delivery job record has to be created separately. Where a customer making the request is new to SDL then a customer record has to be created (this is done directly through Internet requests). - Customers that are registered for online access to the system may identify a particular delivery job from their records and track the whereabouts of that parcel. This will show its current status e.g. awaiting collection, on truck in transit etc. - The payment method for delivery services varies depending upon the type of customer. For private individual customers credit card details are required to be recorded at the time of the delivery request. The card payment will be processed just prior to collection of the consignment. Business customers will be invoiced weekly. Delivery jobs undertaken for HECO are invoiced weekly directly to HECO and not to the independent retailers. An invoice may be for one or more delivery jobs. Once paid, the payment status of each delivery job will be updated. - Delivery schedules (i.e. the route for collections/deliveries taken by the truck) are created for each truck for each day using the address information from the delivery job records. A request for a collection may be incorporated into an existing schedule once the driver has started on the route provided that it can easily be included without too great a disruption to the driver's schedule. This is achieved by locating a truck nearest to the pick-up point and depending upon subsequent stopping points, modifying the schedule to include that call. Route changes will be transmitted to the driver's handheld device which they will also use to acknowledge its receipt. Where routes cannot be easily changed in this way, the job will be incorporated into a schedule for the following day. - At the start of each day a driver will be handed their delivery schedule. Just immediately prior to the start of their journey they will use their handheld device to set the start of the driving period. The will also set the end of the driving period when they finish deliveries. The same mechanism is used to record breaks taken during the day. The fleet manager will check that these times match the odometer record in order to ensure legal compliance. The handheld devices are used by the driver to record collection of jobs and also to record job deliveries. The latter will require a customer signature recorded electronically on the device. - A maintenance record is kept for each truck which contains the date/type (including MOT) of its next service; weekly check date; road tax expiry date; and details of any reported faults and subsequent repairs. - Drivers like to use the same truck when they can so a truck will be "allocated" to a specific driver. However, when a vehicle is off the road for repair/service a different truck will be allocated to that driver. Similarly, when a driver is on holiday then that truck may be allocated to a different driver in the interim. The Ilse Case Descrintion