Kenyan pastoralists need a mobile portal that provides them with a platform to market their products and access critical information relevant to livestock management. Mobile portals and other wireless technologies have greater implications for improved livestock management  . They have the potential to link pastoralists to the global animal market, aid in automatic identification and tracking of animals via Radio-Frequency identification (RFID) systems and enable access to scientific knowledge on animal husbandry  . Many studies have highlighted problems facing the livestock sector as lack of market information and access, gabs in animal supply chain, inadequate knowledge about proper herding, livestock diseases as well as climate change and dwindling grazing grounds    . Mobile web can help solve some of these problems facing Kenyan pastoralists.
The activities of designing and implementing the mobile portal have been guided by systems development life cycle (SDLC). SDLC is a proven methodology for developing software systems. SDLC comprises of four key steps: planning and selection, analysis, design and implementation  . Planning and selection is about identifying problems and selecting the right course of action  .
2. System Analysis
System analysis is composed of two activities: requirements gathering and requirements analysis  . Requirements analysis involves techniques for structuring the information discovered during requirements determination, and they include use cases, data flow diagrams (DFD), flowcharts and decision tables, among others.
This study has used use cases and DFD level 0 to structure user requirements, a choice based on their ease of use and effectiveness in modeling user requirements.
The portal users were categorized into a number of user classes, determined by access privileges enjoyed or their occupations. Grouping by access rights yields two user groups―ordinary users and administrators―while grouping by occupation yields five users, namely: herder/trader, web master, weather system, Vet/ livestock officer and GOK/NGOs.
Two use cases and a context diagram (DFD) were used to model the requirements of these users.
2.1. Use Cases
A Use Case is a means of expressing user requirements; it represents how a system interacts with its environment by illustrating the activities that are performed by the users of the system and the system’s responses  .
2.2. Data Flow Diagrams (DFDs)
A DFD is a graphical tool that allows system analysts to show flow of data in an information system; it shows the main inputs and outputs of the system and the system main users  . There are two types of DFDs: context level DFD (level 0) and exploded DFDs.
A context diagram is composed of external entities, the system and data flows  . Figure 3 represents a DFD level 0 (context diagram) for the portal showing the five occupational users.
Figure 1. End user use cases.
Figure 2. Administrator use cases.
Figure 3. Context diagram for mobile portal.
3. System Design
System design is the determination of the overall system architecture―consisting of a set of physical processing components, hardware, software, people, and the communication among them―that will satisfy the system’s essential requirements  . Key system design activities include architecture design, user interface design and database design  .
In this section, a description of how two design activities: web application design and database design, were effectively used to design the proposed web portal is given.
3.1. Web Application Design
In web application design, system architecture has to be fully described and its components specified.
The mobile portal has a 3-tier architecture composed of the view/presentation layer (tier 1), the application layer (tier 2) and the data layer (tier 3), alternatively called the MVC model  .
Tier 2, the application layer (controller), handles processing of application logics and database accesses  . Apache web server (or IIS), JSP engine and tomcat represent the portal’s tier 2.
Web servers parse HTTP requests from clients (the browsers), JSP engine processes JSP scripts and tomcat compiles and runs action Servlets.
Tier 3―data/model layer―consist of MySQL database management system (DBMS), database tables, stored procedures and views  .
3.2. Database Design
To design the database for the portal, Entity Relationship (ER) diagram, normalized tables and views were used. Entity relationship diagram is a graphical representation of database tables  . The main components of ER are entities, the relationships that can exist among them and the constraints  . Figure 4 is an ER diagram for the portal showing 8 tables, their columns and relationships among tables. ER is the most convenient strategy to describe data relationships and rules, and to outline key modules for the portal.
4. System Implementation
System implementation consists of three activities: coding, testing and documentation  . This section describes the coding and testing of the portal.
The portal was coded in JAVA, J2ME, JSP and SQL languages and developed using JDK 8, sun wireless toolkit 2.5.2, Lightweight User Interface Toolkit (LWUIT) 1.4, struts 1.3, tomcat and MySQL.
Wireless toolkit was for compiling and running midlets, MySQL for creating and managing the portal’s database, tomcat for converting JSP scripts into Servelets, compiling and running action Servelets, and struts for managing communications and control between the applications and database engines.
Figure 4. ER diagram for the mobile portal.
Two testing methods: functional testing and integration testing were used to test and examine potential vulnerabilities of the portal. In functional testing, each module is tested alone in an attempt to discover any errors that may exist in the module’s code while in integration testing, modules or functions are combined together and tested collectively as a related group  . To functionally test modules of the portal, a number of test cases were conducted including input data validation for input forms such as user registration, login, and update price forms, testing click-ability of action buttons and workability of file upload while integration tests were run on the portal for potential bugs and usability issues such as authentication of users, the portal in different browsers and devices, examining together upload and download functionalities among others.
Some of the constraints faced by pastoralists against maximizing their livestock productivity arise from shortage of market information, poor information access, and lack of access to livestock insurance among others. Remedies to these problems may take a variety of forms from technological, socio-economic, policy-based etc. But on the list of viable technological solutions is a mobile web with the potential to linking the pastoralists to the global livestock market and enabling access to up-to-date market information and other needed information services. The study was therefore based on designing and implementing a workable mobile portal for Kenyan pastoralists. The portal was successfully developed and implemented.